81023137 has 16 divisors (see below), whose sum is σ = 89867008. Its totient is φ = 72576000.

The previous prime is 81023123. The next prime is 81023149. The reversal of 81023137 is 73132018.

It is a cyclic number.

It is not a de Polignac number, because 81023137 - 2⁷ = 81023009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81023237) 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, 107512 + ... + 108262.

It is an arithmetic number, because the mean of its divisors is an integer number (5616688).

Almost surely, 2^81023137 is an apocalyptic number.

It is an amenable number.

81023137 is a deficient number, since it is larger than the sum of its proper divisors (8843871).

81023137 is a wasteful number, since it uses less digits than its factorization.

81023137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 81023137 is about 9001.2852971117. The cubic root of 81023137 is about 432.7160638720.

The spelling of 81023137 in words is "eighty-one million, twenty-three thousand, one hundred thirty-seven".