77978020 has 48 divisors (see below), whose sum is σ = 170247168. Its totient is φ = 29969280.

The previous prime is 77978011. The next prime is 77978039. The reversal of 77978020 is 2087977.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

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 15 ways as a sum of consecutive naturals, for example, 106897 + ... + 107623.

It is an arithmetic number, because the mean of its divisors is an integer number (3546816).

Almost surely, 2^77978020 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77978020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85123584).

77978020 is an abundant number, since it is smaller than the sum of its proper divisors (92269148).

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

77978020 is a wasteful number, since it uses less digits than its factorization.

77978020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940 (or 938 counting only the distinct ones).

The product of its (nonzero) digits is 49392, while the sum is 40.

The square root of 77978020 is about 8830.5164061905. The cubic root of 77978020 is about 427.2257306225.

The spelling of 77978020 in words is "seventy-seven million, nine hundred seventy-eight thousand, twenty".