639401007 has 16 divisors (see below), whose sum is σ = 976453632. Its totient is φ = 364573920.

The previous prime is 639400969. The next prime is 639401023. The reversal of 639401007 is 700104936.

It is a happy number.

It is not a de Polignac number, because 639401007 - 2¹⁰ = 639399983 is a prime.

It is a super-2 number, since 2×639401007² = 817667295505228098, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639421007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23343 + ... + 42704.

It is an arithmetic number, because the mean of its divisors is an integer number (61028352).

Almost surely, 2^639401007 is an apocalyptic number.

639401007 is a deficient number, since it is larger than the sum of its proper divisors (337052625).

639401007 is a wasteful number, since it uses less digits than its factorization.

639401007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66518.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 639401007 is about 25286.3798713853. The cubic root of 639401007 is about 861.5049397400.

The spelling of 639401007 in words is "six hundred thirty-nine million, four hundred one thousand, seven".