77508981 has 48 divisors (see below), whose sum is σ = 128314368. Its totient is φ = 46364400.

The previous prime is 77508953. The next prime is 77508997. The reversal of 77508981 is 18980577.

It is not a de Polignac number, because 77508981 - 2²⁵ = 43954549 is a prime.

It is a super-2 number, since 2×77508981² = 12015284271316722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77508931) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 285876 + ... + 286146.

It is an arithmetic number, because the mean of its divisors is an integer number (2673216).

Almost surely, 2^77508981 is an apocalyptic number.

It is an amenable number.

77508981 is a deficient number, since it is larger than the sum of its proper divisors (50805387).

77508981 is a wasteful number, since it uses less digits than its factorization.

77508981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404 (or 392 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The square root of 77508981 is about 8803.9185025760. The cubic root of 77508981 is about 426.3674175941.

The spelling of 77508981 in words is "seventy-seven million, five hundred eight thousand, nine hundred eighty-one".