638693201 has 2 divisors, whose sum is σ = 638693202. Its totient is φ = 638693200.

The previous prime is 638693197. The next prime is 638693243. The reversal of 638693201 is 102396836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 543123025 + 95570176 = 23305^2 + 9776^2 .

It is a cyclic number.

It is not a de Polignac number, because 638693201 - 2² = 638693197 is a prime.

It is not a weakly prime, because it can be changed into another prime (638693261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319346600 + 319346601.

It is an arithmetic number, because the mean of its divisors is an integer number (319346601).

Almost surely, 2^638693201 is an apocalyptic number.

It is an amenable number.

638693201 is a deficient number, since it is larger than the sum of its proper divisors (1).

638693201 is an equidigital number, since it uses as much as digits as its factorization.

638693201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 638693201 is about 25272.3802005272. The cubic root of 638693201 is about 861.1869319473.

The spelling of 638693201 in words is "six hundred thirty-eight million, six hundred ninety-three thousand, two hundred one".