78238839 has 24 divisors (see below), whose sum is σ = 125541360. Its totient is φ = 43163904.

The previous prime is 78238819. The next prime is 78238843. The reversal of 78238839 is 93883287.

It is not a de Polignac number, because 78238839 - 2⁵ = 78238807 is a prime.

It is a super-2 number, since 2×78238839² = 12242631856135842, which contains 22 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78238819) 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, 4914 + ... + 13439.

It is an arithmetic number, because the mean of its divisors is an integer number (5230890).

Almost surely, 2^78238839 is an apocalyptic number.

78238839 is a deficient number, since it is larger than the sum of its proper divisors (47302521).

78238839 is a wasteful number, since it uses less digits than its factorization.

78238839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18399 (or 18392 counting only the distinct ones).

The product of its digits is 580608, while the sum is 48.

The square root of 78238839 is about 8845.2721269614. The cubic root of 78238839 is about 427.7015253128.

It can be divided in two parts, 782 and 38839, that added together give a triangular number (39621 = T₂₈₁).

The spelling of 78238839 in words is "seventy-eight million, two hundred thirty-eight thousand, eight hundred thirty-nine".