78785820 has 72 divisors (see below), whose sum is σ = 253051344. Its totient is φ = 19772928.

The previous prime is 78785813. The next prime is 78785821. The reversal of 78785820 is 2858787.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78785821) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9814 + ... + 15933.

It is an arithmetic number, because the mean of its divisors is an integer number (3514602).

Almost surely, 2^78785820 is an apocalyptic number.

It is an amenable number.

78785820 is an abundant number, since it is smaller than the sum of its proper divisors (174265524).

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

78785820 is a wasteful number, since it uses less digits than its factorization.

78785820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25779 (or 25774 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 45.

The square root of 78785820 is about 8876.1376735605. The cubic root of 78785820 is about 428.6959228802.

The spelling of 78785820 in words is "seventy-eight million, seven hundred eighty-five thousand, eight hundred twenty".