78638004 has 18 divisors (see below), whose sum is σ = 198779490. Its totient is φ = 26212656.

The previous prime is 78637991. The next prime is 78638011. The reversal of 78638004 is 40083687.

It can be written as a sum of positive squares in only one way, i.e., 68062500 + 10575504 = 8250^2 + 3252^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 2184389 = 78638004 / (7 + 8 + 6 + 3 + 8 + 0 + 0 + 4).

It is a self number, because there is not a number n which added to its sum of digits gives 78638004.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1092159 + ... + 1092230.

It is an arithmetic number, because the mean of its divisors is an integer number (11043305).

Almost surely, 2^78638004 is an apocalyptic number.

It is an amenable number.

78638004 is an abundant number, since it is smaller than the sum of its proper divisors (120141486).

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

78638004 is a wasteful number, since it uses less digits than its factorization.

78638004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2184399 (or 2184394 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 78638004 is about 8867.8071697574. The cubic root of 78638004 is about 428.4276521525.

The spelling of 78638004 in words is "seventy-eight million, six hundred thirty-eight thousand, four".