77971964 has 12 divisors (see below), whose sum is σ = 155943984. Its totient is φ = 33416544.

The previous prime is 77971939. The next prime is 77972023. The reversal of 77971964 is 46917977.

It is a happy number.

77971964 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1392329 + ... + 1392384.

It is an arithmetic number, because the mean of its divisors is an integer number (12995332).

Almost surely, 2^77971964 is an apocalyptic number.

It is an amenable number.

77971964 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77971964 is a wasteful number, since it uses less digits than its factorization.

77971964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2784724 (or 2784722 counting only the distinct ones).

The product of its digits is 666792, while the sum is 50.

The square root of 77971964 is about 8830.1734977292. The cubic root of 77971964 is about 427.2146704716.

The spelling of 77971964 in words is "seventy-seven million, nine hundred seventy-one thousand, nine hundred sixty-four".