78738431 has 4 divisors (see below), whose sum is σ = 79735200. Its totient is φ = 77741664.

The previous prime is 78738427. The next prime is 78738437. The reversal of 78738431 is 13483787.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13483787 = 19 ⋅709673.

It is a cyclic number.

It is not a de Polignac number, because 78738431 - 2² = 78738427 is a prime.

It is a super-2 number, since 2×78738431² = 12399481032683522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78738437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 498266 + ... + 498423.

It is an arithmetic number, because the mean of its divisors is an integer number (19933800).

Almost surely, 2^78738431 is an apocalyptic number.

78738431 is a deficient number, since it is larger than the sum of its proper divisors (996769).

78738431 is an equidigital number, since it uses as much as digits as its factorization.

78738431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 996768.

The product of its digits is 112896, while the sum is 41.

The square root of 78738431 is about 8873.4678114027. The cubic root of 78738431 is about 428.6099533252.

The spelling of 78738431 in words is "seventy-eight million, seven hundred thirty-eight thousand, four hundred thirty-one".