81507 has 8 divisors (see below), whose sum is σ = 110160. Its totient is φ = 53600.

The previous prime is 81463. The next prime is 81509. The reversal of 81507 is 70518.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81507 - 2¹⁴ = 65123 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (81509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 169 + ... + 437.

It is an arithmetic number, because the mean of its divisors is an integer number (13770).

2⁸¹⁵⁰⁷ is an apocalyptic number.

81507 is a deficient number, since it is larger than the sum of its proper divisors (28653).

81507 is a wasteful number, since it uses less digits than its factorization.

81507 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373.

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 81507 is about 285.4943081744. The cubic root of 81507 is about 43.3575735515.

The spelling of 81507 in words is "eighty-one thousand, five hundred seven".