76721978 has 8 divisors (see below), whose sum is σ = 116659668. Its totient is φ = 37835424.

The previous prime is 76721917. The next prime is 76721999. The reversal of 76721978 is 87912767.

It can be written as a sum of positive squares in 2 ways, for example, as 68178049 + 8543929 = 8257^2 + 2923^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262601 + ... + 262892.

Almost surely, 2^76721978 is an apocalyptic number.

76721978 is a deficient number, since it is larger than the sum of its proper divisors (39937690).

76721978 is a wasteful number, since it uses less digits than its factorization.

76721978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525568.

The product of its digits is 296352, while the sum is 47.

The square root of 76721978 is about 8759.1082879480. The cubic root of 76721978 is about 424.9194366324.

The spelling of 76721978 in words is "seventy-six million, seven hundred twenty-one thousand, nine hundred seventy-eight".