638239612201 has 9 divisors (see below), whose sum is σ = 639920913303. Its totient is φ = 636562723200.

The previous prime is 638239612151. The next prime is 638239612229. The reversal of 638239612201 is 102216932836.

The square root of 638239612201 is 798899.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 636646005801 + 1593606400 = 797901^2 + 39920^2 .

It is not a de Polignac number, because 638239612201 - 2²¹ = 638237515049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638239612261) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 398649801 + ... + 398651401.

Almost surely, 2^638239612201 is an apocalyptic number.

638239612201 is the 798899-th square number.

638239612201 is the 399450-th centered octagonal number.

It is an amenable number.

638239612201 is a deficient number, since it is larger than the sum of its proper divisors (1681301102).

638239612201 is an frugal number, since it uses more digits than its factorization.

638239612201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4200 (or 2100 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 43.

The spelling of 638239612201 in words is "six hundred thirty-eight billion, two hundred thirty-nine million, six hundred twelve thousand, two hundred one".