77978140 has 12 divisors (see below), whose sum is σ = 163754136. Its totient is φ = 31191248.

The previous prime is 77978137. The next prime is 77978171. The reversal of 77978140 is 4187977.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1949434 + ... + 1949473.

It is an arithmetic number, because the mean of its divisors is an integer number (13646178).

Almost surely, 2^77978140 is an apocalyptic number.

It is an amenable number.

77978140 is an abundant number, since it is smaller than the sum of its proper divisors (85775996).

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

77978140 is a wasteful number, since it uses less digits than its factorization.

77978140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3898916 (or 3898914 counting only the distinct ones).

The product of its (nonzero) digits is 98784, while the sum is 43.

The square root of 77978140 is about 8830.5232008075. The cubic root of 77978140 is about 427.2259497743.

The spelling of 77978140 in words is "seventy-seven million, nine hundred seventy-eight thousand, one hundred forty".