76581981 has 12 divisors (see below), whose sum is σ = 126421152. Its totient is φ = 43761096.

The previous prime is 76581961. The next prime is 76582003. The reversal of 76581981 is 18918567.

It is not a de Polignac number, because 76581981 - 2⁶ = 76581917 is a prime.

It is a super-2 number, since 2×76581981² = 11729599627768722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76581961) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 607731 + ... + 607856.

It is an arithmetic number, because the mean of its divisors is an integer number (10535096).

Almost surely, 2^76581981 is an apocalyptic number.

It is an amenable number.

76581981 is a deficient number, since it is larger than the sum of its proper divisors (49839171).

76581981 is a wasteful number, since it uses less digits than its factorization.

76581981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215600 (or 1215597 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 76581981 is about 8751.1131291968. The cubic root of 76581981 is about 424.6608246609.

The spelling of 76581981 in words is "seventy-six million, five hundred eighty-one thousand, nine hundred eighty-one".