77397921 has 12 divisors (see below), whose sum is σ = 116658048. Its totient is φ = 49355064.

The previous prime is 77397913. The next prime is 77397937. The reversal of 77397921 is 12979377.

It is not a de Polignac number, because 77397921 - 2³ = 77397913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77397961) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 186745 + ... + 187158.

It is an arithmetic number, because the mean of its divisors is an integer number (9721504).

Almost surely, 2^77397921 is an apocalyptic number.

It is an amenable number.

77397921 is a deficient number, since it is larger than the sum of its proper divisors (39260127).

77397921 is a wasteful number, since it uses less digits than its factorization.

77397921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373932 (or 373929 counting only the distinct ones).

The product of its digits is 166698, while the sum is 45.

The square root of 77397921 is about 8797.6088228564. The cubic root of 77397921 is about 426.1636777636.

The spelling of 77397921 in words is "seventy-seven million, three hundred ninety-seven thousand, nine hundred twenty-one".