78805990 has 16 divisors (see below), whose sum is σ = 142567200. Its totient is φ = 31363992.

The previous prime is 78805973. The next prime is 78806009. The reversal of 78805990 is 9950887.

It is a self number, because there is not a number n which added to its sum of digits gives 78805990.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395911 + ... + 396109.

It is an arithmetic number, because the mean of its divisors is an integer number (8910450).

Almost surely, 2^78805990 is an apocalyptic number.

78805990 is a deficient number, since it is larger than the sum of its proper divisors (63761210).

78805990 is an frugal number, since it uses more digits than its factorization.

78805990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 46.

The square root of 78805990 is about 8877.2737932318. The cubic root of 78805990 is about 428.7325033163.

The spelling of 78805990 in words is "seventy-eight million, eight hundred five thousand, nine hundred ninety".