639327021 has 8 divisors (see below), whose sum is σ = 889498560. Its totient is φ = 407686752.

The previous prime is 639327019. The next prime is 639327023. The reversal of 639327021 is 120723936.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (639327019) and next prime (639327023).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 639327021 - 2¹ = 639327019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639327023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4632736 + ... + 4632873.

It is an arithmetic number, because the mean of its divisors is an integer number (111187320).

Almost surely, 2^639327021 is an apocalyptic number.

It is an amenable number.

639327021 is a deficient number, since it is larger than the sum of its proper divisors (250171539).

639327021 is a wasteful number, since it uses less digits than its factorization.

639327021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9265635.

The product of its (nonzero) digits is 13608, while the sum is 33.

The square root of 639327021 is about 25284.9168675715. The cubic root of 639327021 is about 861.4717098042.

The spelling of 639327021 in words is "six hundred thirty-nine million, three hundred twenty-seven thousand, twenty-one".