247638431 has 2 divisors, whose sum is σ = 247638432. Its totient is φ = 247638430.

The previous prime is 247638427. The next prime is 247638449. The reversal of 247638431 is 134836742.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 247638431 - 2² = 247638427 is a prime.

It is a super-2 number, since 2×247638431² = 122649585016283522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (247638421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123819215 + 123819216.

It is an arithmetic number, because the mean of its divisors is an integer number (123819216).

Almost surely, 2^247638431 is an apocalyptic number.

247638431 is a deficient number, since it is larger than the sum of its proper divisors (1).

247638431 is an equidigital number, since it uses as much as digits as its factorization.

247638431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 38.

The square root of 247638431 is about 15736.5317335174. The cubic root of 247638431 is about 627.9706524414.

The spelling of 247638431 in words is "two hundred forty-seven million, six hundred thirty-eight thousand, four hundred thirty-one".