78621380 has 24 divisors (see below), whose sum is σ = 165278232. Its totient is φ = 31415552.

The previous prime is 78621377. The next prime is 78621397. The reversal of 78621380 is 8312687.

It can be written as a sum of positive squares in 4 ways, for example, as 9132484 + 69488896 = 3022^2 + 8336^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 78621380.

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, 28544 + ... + 31176.

It is an arithmetic number, because the mean of its divisors is an integer number (6886593).

Almost surely, 2^78621380 is an apocalyptic number.

It is an amenable number.

78621380 is an abundant number, since it is smaller than the sum of its proper divisors (86656852).

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

78621380 is a wasteful number, since it uses less digits than its factorization.

78621380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4135 (or 4133 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 78621380 is about 8866.8697971719. The cubic root of 78621380 is about 428.3974602908.

The spelling of 78621380 in words is "seventy-eight million, six hundred twenty-one thousand, three hundred eighty".