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1357 = 2359

1357 has 4 divisors (see below), whose sum is σ = 1440. Its totient is φ = 1276.

The previous prime is 1327. The next prime is 1361. The reversal of 1357 is 7531.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7531 = 17443.

It is a cyclic number.

It is not a de Polignac number, because 1357 - 27 = 1229 is a prime.

It is a Duffinian number.

1357 is a lucky number.

It is a straight-line number, since its digits are in arithmetic progression.

It is a plaindrome in base 10 and base 14.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 1357.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7 + ... + 52.

It is an arithmetic number, because the mean of its divisors is an integer number (360).

It is an amenable number.

1357 is a deficient number, since it is larger than the sum of its proper divisors (83).

1357 is an equidigital number, since it uses as much as digits as its factorization.

1357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82.

The product of its digits is 105, while the sum is 16.

The square root of 1357 is about 36.8374809128. The cubic root of 1357 is about 11.0711639598.

Multiplying 1357 by its sum of digits (16), we get a palindrome (21712).

Adding to 1357 its reverse (7531), we get a palindrome (8888).

It can be divided in two parts, 13 and 57, that multiplied together give a triangular number (741 = T38).

The spelling of 1357 in words is "one thousand, three hundred fifty-seven".

Divisors: 1 23 59 1357