81657725630 has 16 divisors (see below), whose sum is σ = 158290360704. Its totient is φ = 30150544800.

The previous prime is 81657725587. The next prime is 81657725657. The reversal of 81657725630 is 3652775618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 314068046 + ... + 314068305.

It is an arithmetic number, because the mean of its divisors is an integer number (9893147544).

Almost surely, 2^81657725630 is an apocalyptic number.

81657725630 is a deficient number, since it is larger than the sum of its proper divisors (76632635074).

81657725630 is a wasteful number, since it uses less digits than its factorization.

81657725630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628136371.

The product of its (nonzero) digits is 2116800, while the sum is 50.

The spelling of 81657725630 in words is "eighty-one billion, six hundred fifty-seven million, seven hundred twenty-five thousand, six hundred thirty".