77021978 has 8 divisors (see below), whose sum is σ = 126036000. Its totient is φ = 35009980.

The previous prime is 77021969. The next prime is 77021983. The reversal of 77021978 is 87912077.

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, 1750478 + ... + 1750521.

It is an arithmetic number, because the mean of its divisors is an integer number (15754500).

Almost surely, 2^77021978 is an apocalyptic number.

77021978 is a deficient number, since it is larger than the sum of its proper divisors (49014022).

77021978 is a wasteful number, since it uses less digits than its factorization.

77021978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3501012.

The product of its (nonzero) digits is 49392, while the sum is 41.

The square root of 77021978 is about 8776.2166108181. The cubic root of 77021978 is about 425.4725594853.

The spelling of 77021978 in words is "seventy-seven million, twenty-one thousand, nine hundred seventy-eight".