76521981 has 32 divisors (see below), whose sum is σ = 115430400. Its totient is φ = 44835840.

The previous prime is 76521971. The next prime is 76522003. The reversal of 76521981 is 18912567.

It is not a de Polignac number, because 76521981 - 2⁷ = 76521853 is a prime.

It is a super-2 number, since 2×76521981² = 11711227152328722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76521901) 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, 45015 + ... + 46683.

It is an arithmetic number, because the mean of its divisors is an integer number (3607200).

Almost surely, 2^76521981 is an apocalyptic number.

It is an amenable number.

76521981 is a deficient number, since it is larger than the sum of its proper divisors (38908419).

76521981 is a wasteful number, since it uses less digits than its factorization.

76521981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1749.

The product of its digits is 30240, while the sum is 39.

The square root of 76521981 is about 8747.6843221506. The cubic root of 76521981 is about 424.5498920966.

The spelling of 76521981 in words is "seventy-six million, five hundred twenty-one thousand, nine hundred eighty-one".