81629890580 has 48 divisors (see below), whose sum is σ = 197084918016. Its totient is φ = 27819793920.

The previous prime is 81629890579. The next prime is 81629890609. The reversal of 81629890580 is 8509892618.

It is a super-2 number, since 2×81629890580² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1722341 + ... + 1769100.

It is an arithmetic number, because the mean of its divisors is an integer number (4105935792).

Almost surely, 2^81629890580 is an apocalyptic number.

It is an amenable number.

81629890580 is an abundant number, since it is smaller than the sum of its proper divisors (115455027436).

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

81629890580 is a wasteful number, since it uses less digits than its factorization.

81629890580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3491624 (or 3491622 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 56.

The spelling of 81629890580 in words is "eighty-one billion, six hundred twenty-nine million, eight hundred ninety thousand, five hundred eighty".