81083979520 has 36 divisors (see below), whose sum is σ = 194221472760. Its totient is φ = 32433591296.

The previous prime is 81083979481. The next prime is 81083979541. The reversal of 81083979520 is 2597938018.

It is a super-2 number, since 2×81083979520² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31672150 + ... + 31674709.

It is an arithmetic number, because the mean of its divisors is an integer number (5395040910).

Almost surely, 2^81083979520 is an apocalyptic number.

81083979520 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81083979520 is an abundant number, since it is smaller than the sum of its proper divisors (113137493240).

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

81083979520 is an equidigital number, since it uses as much as digits as its factorization.

81083979520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63346880 (or 63346866 counting only the distinct ones).

The product of its (nonzero) digits is 1088640, while the sum is 52.

The spelling of 81083979520 in words is "eighty-one billion, eighty-three million, nine hundred seventy-nine thousand, five hundred twenty".