639347331 has 8 divisors (see below), whose sum is σ = 974243584. Its totient is φ = 365341320.

The previous prime is 639347329. The next prime is 639347347. The reversal of 639347331 is 133743936.

It is a happy number.

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

It is not a de Polignac number, because 639347331 - 2¹ = 639347329 is a prime.

It is a super-2 number, since 2×639347331² = 817530019313647122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639347331.

It is not an unprimeable number, because it can be changed into a prime (639347351) 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, 15222535 + ... + 15222576.

It is an arithmetic number, because the mean of its divisors is an integer number (121780448).

Almost surely, 2^639347331 is an apocalyptic number.

639347331 is a deficient number, since it is larger than the sum of its proper divisors (334896253).

639347331 is a wasteful number, since it uses less digits than its factorization.

639347331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30445121.

The product of its digits is 122472, while the sum is 39.

The square root of 639347331 is about 25285.3184872170. The cubic root of 639347331 is about 861.4808320555.

The spelling of 639347331 in words is "six hundred thirty-nine million, three hundred forty-seven thousand, three hundred thirty-one".