81625587690 has 32 divisors (see below), whose sum is σ = 196263559296. Its totient is φ = 21726584640.

The previous prime is 81625587679. The next prime is 81625587691. The reversal of 81625587690 is 9678552618.

It is a super-2 number, since 2×81625587690² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81625587690.

It is not an unprimeable number, because it can be changed into a prime (81625587691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2498422 + ... + 2530881.

It is an arithmetic number, because the mean of its divisors is an integer number (6133236228).

Almost surely, 2^81625587690 is an apocalyptic number.

81625587690 is an abundant number, since it is smaller than the sum of its proper divisors (114637971606).

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

81625587690 is a wasteful number, since it uses less digits than its factorization.

81625587690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5029854.

The product of its (nonzero) digits is 7257600, while the sum is 57.

The spelling of 81625587690 in words is "eighty-one billion, six hundred twenty-five million, five hundred eighty-seven thousand, six hundred ninety".