81711500656 has 10 divisors (see below), whose sum is σ = 158316032552. Its totient is φ = 40855750320.

The previous prime is 81711500593. The next prime is 81711500677. The reversal of 81711500656 is 65600511718.

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, 2553484380 + ... + 2553484411.

Almost surely, 2^81711500656 is an apocalyptic number.

It is an amenable number.

81711500656 is a deficient number, since it is larger than the sum of its proper divisors (76604531896).

81711500656 is a wasteful number, since it uses less digits than its factorization.

81711500656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5106968799 (or 5106968793 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 40.

The spelling of 81711500656 in words is "eighty-one billion, seven hundred eleven million, five hundred thousand, six hundred fifty-six".