81308074920 has 32 divisors (see below), whose sum is σ = 243924225120. Its totient is φ = 21682153280.

The previous prime is 81308074907. The next prime is 81308074931. The reversal of 81308074920 is 2947080318.

It is a super-2 number, since 2×81308074920² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338783526 + ... + 338783765.

It is an arithmetic number, because the mean of its divisors is an integer number (7622632035).

Almost surely, 2^81308074920 is an apocalyptic number.

It is an amenable number.

81308074920 is an abundant number, since it is smaller than the sum of its proper divisors (162616150200).

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

81308074920 is a wasteful number, since it uses less digits than its factorization.

81308074920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677567305 (or 677567301 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 42.

The spelling of 81308074920 in words is "eighty-one billion, three hundred eight million, seventy-four thousand, nine hundred twenty".