81745315 has 16 divisors (see below), whose sum is σ = 103910400. Its totient is φ = 61562592.

The previous prime is 81745309. The next prime is 81745319. The reversal of 81745315 is 51354718.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81745315 - 2⁷ = 81745187 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81745319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12846 + ... + 18124.

It is an arithmetic number, because the mean of its divisors is an integer number (6494400).

Almost surely, 2^81745315 is an apocalyptic number.

81745315 is a deficient number, since it is larger than the sum of its proper divisors (22165085).

81745315 is a wasteful number, since it uses less digits than its factorization.

81745315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5466.

The product of its digits is 16800, while the sum is 34.

The square root of 81745315 is about 9041.3115752085. The cubic root of 81745315 is about 433.9978958183.

The spelling of 81745315 in words is "eighty-one million, seven hundred forty-five thousand, three hundred fifteen".