81170265931566 has 32 divisors (see below), whose sum is σ = 185534426568960. Its totient is φ = 23191205782656.

The previous prime is 81170265931493. The next prime is 81170265931589. The reversal of 81170265931566 is 66513956207118.

It is a happy number.

It is a super-2 number, since 2×81170265931566² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9139371 + ... + 15680198.

It is an arithmetic number, because the mean of its divisors is an integer number (5797950830280).

Almost surely, 2^{81170265931566} is an apocalyptic number.

81170265931566 is an abundant number, since it is smaller than the sum of its proper divisors (104364160637394).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81170265931566 is a wasteful number, since it uses less digits than its factorization.

81170265931566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24897448.

The product of its (nonzero) digits is 16329600, while the sum is 60.

The spelling of 81170265931566 in words is "eighty-one trillion, one hundred seventy billion, two hundred sixty-five million, nine hundred thirty-one thousand, five hundred sixty-six".