77908391 has 12 divisors (see below), whose sum is σ = 85890336. Its totient is φ = 70614720.

The previous prime is 77908387. The next prime is 77908393. The reversal of 77908391 is 19380977.

It is not a de Polignac number, because 77908391 - 2² = 77908387 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77908393) 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 11 ways as a sum of consecutive naturals, for example, 51650 + ... + 53136.

It is an arithmetic number, because the mean of its divisors is an integer number (7157528).

Almost surely, 2^77908391 is an apocalyptic number.

77908391 is a deficient number, since it is larger than the sum of its proper divisors (7981945).

77908391 is a wasteful number, since it uses less digits than its factorization.

77908391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1942 (or 1931 counting only the distinct ones).

The product of its (nonzero) digits is 95256, while the sum is 44.

The square root of 77908391 is about 8826.5730042865. The cubic root of 77908391 is about 427.0985317063.

The spelling of 77908391 in words is "seventy-seven million, nine hundred eight thousand, three hundred ninety-one".