76997781 has 12 divisors (see below), whose sum is σ = 127107552. Its totient is φ = 43998696.

The previous prime is 76997771. The next prime is 76997783. The reversal of 76997781 is 18779967.

It is not a de Polignac number, because 76997781 - 2⁶ = 76997717 is a prime.

It is a super-2 number, since 2×76997781² = 11857316557847922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76997783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 611031 + ... + 611156.

It is an arithmetic number, because the mean of its divisors is an integer number (10592296).

Almost surely, 2^76997781 is an apocalyptic number.

It is an amenable number.

76997781 is a deficient number, since it is larger than the sum of its proper divisors (50109771).

76997781 is a wasteful number, since it uses less digits than its factorization.

76997781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222200 (or 1222197 counting only the distinct ones).

The product of its digits is 1333584, while the sum is 54.

The square root of 76997781 is about 8774.8379472216. The cubic root of 76997781 is about 425.4279997458.

The spelling of 76997781 in words is "seventy-six million, nine hundred ninety-seven thousand, seven hundred eighty-one".