81581764525592 has 8 divisors (see below), whose sum is σ = 152965808485500. Its totient is φ = 40790882262792.

The previous prime is 81581764525579. The next prime is 81581764525621. The reversal of 81581764525592 is 29552546718518.

81581764525592 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5098860282842 + ... + 5098860282857.

Almost surely, 2^{81581764525592} is an apocalyptic number.

It is an amenable number.

81581764525592 is a deficient number, since it is larger than the sum of its proper divisors (71384043959908).

81581764525592 is a wasteful number, since it uses less digits than its factorization.

81581764525592 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10197720565705 (or 10197720565701 counting only the distinct ones).

The product of its digits is 241920000, while the sum is 68.

The spelling of 81581764525592 in words is "eighty-one trillion, five hundred eighty-one billion, seven hundred sixty-four million, five hundred twenty-five thousand, five hundred ninety-two".