78444631 has 2 divisors, whose sum is σ = 78444632. Its totient is φ = 78444630.

The previous prime is 78444629. The next prime is 78444643. The reversal of 78444631 is 13644487.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78444631 - 2¹ = 78444629 is a prime.

It is a super-2 number, since 2×78444631² = 12307120265452322, which contains 22 as substring.

Together with 78444629, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78444661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39222315 + 39222316.

It is an arithmetic number, because the mean of its divisors is an integer number (39222316).

Almost surely, 2^78444631 is an apocalyptic number.

78444631 is a deficient number, since it is larger than the sum of its proper divisors (1).

78444631 is an equidigital number, since it uses as much as digits as its factorization.

78444631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 37.

The square root of 78444631 is about 8856.8973687178. The cubic root of 78444631 is about 428.0761921449.

The spelling of 78444631 in words is "seventy-eight million, four hundred forty-four thousand, six hundred thirty-one".