78162431 has 4 divisors (see below), whose sum is σ = 78182832. Its totient is φ = 78142032.

The previous prime is 78162419. The next prime is 78162449. The reversal of 78162431 is 13426187.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78162431 - 2⁶ = 78162367 is a prime.

It is a super-2 number, since 2×78162431² = 12218731239659522, 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 (78162451) 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, 2531 + ... + 12756.

It is an arithmetic number, because the mean of its divisors is an integer number (19545708).

Almost surely, 2^78162431 is an apocalyptic number.

78162431 is a deficient number, since it is larger than the sum of its proper divisors (20401).

78162431 is a wasteful number, since it uses less digits than its factorization.

78162431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20400.

The product of its digits is 8064, while the sum is 32.

The square root of 78162431 is about 8840.9519283842. The cubic root of 78162431 is about 427.5622489521.

The spelling of 78162431 in words is "seventy-eight million, one hundred sixty-two thousand, four hundred thirty-one".