639054401 has 4 divisors (see below), whose sum is σ = 641541252. Its totient is φ = 636567552.

The previous prime is 639054359. The next prime is 639054419. The reversal of 639054401 is 104450936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 475240000 + 163814401 = 21800^2 + 12799^2 .

It is a cyclic number.

It is not a de Polignac number, because 639054401 - 2¹⁴ = 639038017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639054421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1243040 + ... + 1243553.

It is an arithmetic number, because the mean of its divisors is an integer number (160385313).

Almost surely, 2^639054401 is an apocalyptic number.

It is an amenable number.

639054401 is a deficient number, since it is larger than the sum of its proper divisors (2486851).

639054401 is a wasteful number, since it uses less digits than its factorization.

639054401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2486850.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 639054401 is about 25279.5253317779. The cubic root of 639054401 is about 861.3492436277.

The spelling of 639054401 in words is "six hundred thirty-nine million, fifty-four thousand, four hundred one".