78420384 has 108 divisors (see below), whose sum is σ = 259464114. Its totient is φ = 22401792.

The previous prime is 78420383. The next prime is 78420449. The reversal of 78420384 is 48302487.

It can be written as a sum of positive squares in only one way, i.e., 48608784 + 29811600 = 6972^2 + 5460^2 .

It is a super-2 number, since 2×78420384² = 12299513253414912, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (78420383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11334 + ... + 16890.

Almost surely, 2^78420384 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78420384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129732057).

78420384 is an abundant number, since it is smaller than the sum of its proper divisors (181043730).

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

78420384 is a wasteful number, since it uses less digits than its factorization.

78420384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5587 (or 5569 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The square root of 78420384 is about 8855.5284427300. The cubic root of 78420384 is about 428.0320819111.

The spelling of 78420384 in words is "seventy-eight million, four hundred twenty thousand, three hundred eighty-four".