81615070831 has 8 divisors (see below), whose sum is σ = 94008811520. Its totient is φ = 69404941368.

The previous prime is 81615070819. The next prime is 81615070853. The reversal of 81615070831 is 13807051618.

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

It is not a de Polignac number, because 81615070831 - 2⁵ = 81615070799 is a prime.

It is a super-2 number, since 2×81615070831² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81615070811) 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, 45901851 + ... + 45903628.

It is an arithmetic number, because the mean of its divisors is an integer number (11751101440).

Almost surely, 2^81615070831 is an apocalyptic number.

81615070831 is a deficient number, since it is larger than the sum of its proper divisors (12393740689).

81615070831 is a wasteful number, since it uses less digits than its factorization.

81615070831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91805613.

The product of its (nonzero) digits is 40320, while the sum is 40.

The spelling of 81615070831 in words is "eighty-one billion, six hundred fifteen million, seventy thousand, eight hundred thirty-one".