638051831 has 2 divisors, whose sum is σ = 638051832. Its totient is φ = 638051830.

The previous prime is 638051801. The next prime is 638051849. The reversal of 638051831 is 138150836.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638051831 - 2⁶ = 638051767 is a prime.

It is a super-2 number, since 2×638051831² = 814220278084905122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 638051791 and 638051800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638051801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319025915 + 319025916.

It is an arithmetic number, because the mean of its divisors is an integer number (319025916).

Almost surely, 2^638051831 is an apocalyptic number.

638051831 is a deficient number, since it is larger than the sum of its proper divisors (1).

638051831 is an equidigital number, since it uses as much as digits as its factorization.

638051831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 638051831 is about 25259.6878642631. The cubic root of 638051831 is about 860.8985699974.

The spelling of 638051831 in words is "six hundred thirty-eight million, fifty-one thousand, eight hundred thirty-one".