639354387 has 16 divisors (see below), whose sum is σ = 1007850240. Its totient is φ = 352746912.

The previous prime is 639354371. The next prime is 639354403. The reversal of 639354387 is 783453936.

It is an interprime number because it is at equal distance from previous prime (639354371) and next prime (639354403).

It is not a de Polignac number, because 639354387 - 2⁴ = 639354371 is a prime.

It is a super-2 number, since 2×639354387² = 817548064352291538, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (639354307) 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, 524313 + ... + 525530.

It is an arithmetic number, because the mean of its divisors is an integer number (62990640).

Almost surely, 2^639354387 is an apocalyptic number.

639354387 is a deficient number, since it is larger than the sum of its proper divisors (368495853).

639354387 is a wasteful number, since it uses less digits than its factorization.

639354387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1049882.

The product of its digits is 1632960, while the sum is 48.

The square root of 639354387 is about 25285.4580144398. The cubic root of 639354387 is about 861.4840012178.

The spelling of 639354387 in words is "six hundred thirty-nine million, three hundred fifty-four thousand, three hundred eighty-seven".