77213992 has 8 divisors (see below), whose sum is σ = 144776250. Its totient is φ = 38606992.

The previous prime is 77213989. The next prime is 77213993. The reversal of 77213992 is 29931277.

It can be written as a sum of positive squares in only one way, i.e., 72829156 + 4384836 = 8534^2 + 2094^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (77213993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4825867 + ... + 4825882.

Almost surely, 2^77213992 is an apocalyptic number.

It is an amenable number.

77213992 is a deficient number, since it is larger than the sum of its proper divisors (67562258).

77213992 is a wasteful number, since it uses less digits than its factorization.

77213992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9651755 (or 9651751 counting only the distinct ones).

The product of its digits is 47628, while the sum is 40.

The square root of 77213992 is about 8787.1492533130. The cubic root of 77213992 is about 425.8258304810.

The spelling of 77213992 in words is "seventy-seven million, two hundred thirteen thousand, nine hundred ninety-two".