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315 = 3257

315 has 12 divisors (see below), whose sum is σ = 624. Its totient is φ = 144.

The previous prime is 313. The next prime is 317. The reversal of 315 is 513.

It is an interprime number because it is at equal distance from previous prime (313) and next prime (317).

It is not a de Polignac number, because 315 - 21 = 313 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a D-number.

It is one of the 548 Lynch-Bell numbers.

Its product of digits (15) is a multiple of the sum of its prime divisors (15).

It is a plaindrome in base 11, base 12 and base 16.

It is a nialpdrome in base 7.

It is a junction number, because it is equal to n+sod(n) for n = 297 and 306.

It is not an unprimeable number, because it can be changed into a prime (311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42 + ... + 48.

It is an arithmetic number, because the mean of its divisors is an integer number (52).

315 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

315 is a deficient number, since it is larger than the sum of its proper divisors (309).

315 is a wasteful number, since it uses less digits than its factorization.

315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18 (or 15 counting only the distinct ones).

The product of its digits is 15, while the sum is 9.

The square root of 315 is about 17.7482393493. The cubic root of 315 is about 6.8040921160.

Subtracting from 315 its product of digits (15), we obtain a triangular number (300 = T24).

315 divided by its product of digits (15) gives a triangular number (21 = T6).

Adding to 315 its reverse (513), we get a palindrome (828).

It can be divided in two parts, 31 and 5, that added together give a triangular number (36 = T8).

The spelling of 315 in words is "three hundred fifteen", and thus it is an aban number and an oban number.

Divisors: 1 3 5 7 9 15 21 35 45 63 105 315