81119974521 has 32 divisors (see below), whose sum is σ = 112034119680. Its totient is φ = 52184044224.

The previous prime is 81119974513. The next prime is 81119974531. The reversal of 81119974521 is 12547991118.

It is not a de Polignac number, because 81119974521 - 2³ = 81119974513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81119974531) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2347656 + ... + 2381958.

It is an arithmetic number, because the mean of its divisors is an integer number (3501066240).

Almost surely, 2^81119974521 is an apocalyptic number.

It is an amenable number.

81119974521 is a deficient number, since it is larger than the sum of its proper divisors (30914145159).

81119974521 is a wasteful number, since it uses less digits than its factorization.

81119974521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34605.

The product of its digits is 181440, while the sum is 48.

The spelling of 81119974521 in words is "eighty-one billion, one hundred nineteen million, nine hundred seventy-four thousand, five hundred twenty-one".