77879820 has 48 divisors (see below), whose sum is σ = 223963488. Its totient is φ = 20206080.

The previous prime is 77879807. The next prime is 77879827. The reversal of 77879820 is 2897877.

It is a self number, because there is not a number n which added to its sum of digits gives 77879820.

It is not an unprimeable number, because it can be changed into a prime (77879827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15321 + ... + 19760.

It is an arithmetic number, because the mean of its divisors is an integer number (4665906).

Almost surely, 2^77879820 is an apocalyptic number.

It is an amenable number.

77879820 is an abundant number, since it is smaller than the sum of its proper divisors (146083668).

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

77879820 is a wasteful number, since it uses less digits than its factorization.

77879820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35130 (or 35128 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 48.

The square root of 77879820 is about 8824.9543908170. The cubic root of 77879820 is about 427.0463160037.

The spelling of 77879820 in words is "seventy-seven million, eight hundred seventy-nine thousand, eight hundred twenty".