77991338 has 16 divisors (see below), whose sum is σ = 120887424. Its totient is φ = 37708560.

The previous prime is 77991317. The next prime is 77991343. The reversal of 77991338 is 83319977.

It is a junction number, because it is equal to n+sod(n) for n = 77991292 and 77991301.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9203 + ... + 15513.

It is an arithmetic number, because the mean of its divisors is an integer number (7555464).

Almost surely, 2^77991338 is an apocalyptic number.

77991338 is a deficient number, since it is larger than the sum of its proper divisors (42896086).

77991338 is a wasteful number, since it uses less digits than its factorization.

77991338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6517.

The product of its digits is 285768, while the sum is 47.

The square root of 77991338 is about 8831.2704635290. The cubic root of 77991338 is about 427.2500514435.

The spelling of 77991338 in words is "seventy-seven million, nine hundred ninety-one thousand, three hundred thirty-eight".