77808420 has 72 divisors (see below), whose sum is σ = 248451840. Its totient is φ = 19656000.

The previous prime is 77808413. The next prime is 77808431. The reversal of 77808420 is 2480877.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7956 + ... + 14795.

It is an arithmetic number, because the mean of its divisors is an integer number (3450720).

Almost surely, 2^77808420 is an apocalyptic number.

It is an amenable number.

77808420 is an abundant number, since it is smaller than the sum of its proper divisors (170643420).

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

77808420 is a wasteful number, since it uses less digits than its factorization.

77808420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22785 (or 22780 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 77808420 is about 8820.9081165150. The cubic root of 77808420 is about 426.9157711473.

The spelling of 77808420 in words is "seventy-seven million, eight hundred eight thousand, four hundred twenty".