639384001 has 4 divisors (see below), whose sum is σ = 639452500. Its totient is φ = 639315504.

The previous prime is 639383993. The next prime is 639384007. The reversal of 639384001 is 100483936.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 283080625 + 356303376 = 16825^2 + 18876^2 .

It is a cyclic number.

It is not a de Polignac number, because 639384001 - 2³ = 639383993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639384007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17526 + ... + 39823.

It is an arithmetic number, because the mean of its divisors is an integer number (159863125).

Almost surely, 2^639384001 is an apocalyptic number.

It is an amenable number.

639384001 is a deficient number, since it is larger than the sum of its proper divisors (68499).

639384001 is a wasteful number, since it uses less digits than its factorization.

639384001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68498.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 639384001 is about 25286.0436011647. The cubic root of 639384001 is about 861.4973019233.

The spelling of 639384001 in words is "six hundred thirty-nine million, three hundred eighty-four thousand, one".