639628601 has 4 divisors (see below), whose sum is σ = 643864704. Its totient is φ = 635392500.

The previous prime is 639628579. The next prime is 639628603. The reversal of 639628601 is 106826936.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 639628601 - 2¹⁸ = 639366457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639628603) 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, 2117825 + ... + 2118126.

It is an arithmetic number, because the mean of its divisors is an integer number (160966176).

Almost surely, 2^639628601 is an apocalyptic number.

It is an amenable number.

639628601 is a deficient number, since it is larger than the sum of its proper divisors (4236103).

639628601 is a wasteful number, since it uses less digits than its factorization.

639628601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4236102.

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 639628601 is about 25290.8797988524. The cubic root of 639628601 is about 861.6071448213.

The spelling of 639628601 in words is "six hundred thirty-nine million, six hundred twenty-eight thousand, six hundred one".