77936391 has 16 divisors (see below), whose sum is σ = 124343520. Its totient is φ = 47960640.

The previous prime is 77936377. The next prime is 77936401. The reversal of 77936391 is 19363977.

77936391 is a `hidden beast` number, since 7 + 7 + 9 + 3 + 639 + 1 = 666.

It is not a de Polignac number, because 77936391 - 2¹¹ = 77934343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77936371) 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 15 ways as a sum of consecutive naturals, for example, 110670 + ... + 111371.

It is an arithmetic number, because the mean of its divisors is an integer number (7771470).

Almost surely, 2^77936391 is an apocalyptic number.

77936391 is a deficient number, since it is larger than the sum of its proper divisors (46407129).

77936391 is a wasteful number, since it uses less digits than its factorization.

77936391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222063 (or 222057 counting only the distinct ones).

The product of its digits is 214326, while the sum is 45.

The square root of 77936391 is about 8828.1589813505. The cubic root of 77936391 is about 427.1496914782.

The spelling of 77936391 in words is "seventy-seven million, nine hundred thirty-six thousand, three hundred ninety-one".