638272231 has 2 divisors, whose sum is σ = 638272232. Its totient is φ = 638272230.

The previous prime is 638272199. The next prime is 638272277. The reversal of 638272231 is 132272836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638272231 - 2⁵ = 638272199 is a prime.

It is a super-2 number, since 2×638272231² = 814782881731434722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638272291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319136115 + 319136116.

It is an arithmetic number, because the mean of its divisors is an integer number (319136116).

Almost surely, 2^638272231 is an apocalyptic number.

638272231 is a deficient number, since it is larger than the sum of its proper divisors (1).

638272231 is an equidigital number, since it uses as much as digits as its factorization.

638272231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 34.

The square root of 638272231 is about 25264.0501701528. The cubic root of 638272231 is about 860.9976843078.

The spelling of 638272231 in words is "six hundred thirty-eight million, two hundred seventy-two thousand, two hundred thirty-one".