639962390 has 16 divisors (see below), whose sum is σ = 1152526320. Its totient is φ = 255852960.

The previous prime is 639962377. The next prime is 639962423. The reversal of 639962390 is 93269936.

It is a super-2 number, since 2×639962390² = 819103721229024200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5225 + ... + 36155.

It is an arithmetic number, because the mean of its divisors is an integer number (72032895).

Almost surely, 2^639962390 is an apocalyptic number.

639962390 is a deficient number, since it is larger than the sum of its proper divisors (512563930).

639962390 is a wasteful number, since it uses less digits than its factorization.

639962390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33007.

The product of its (nonzero) digits is 472392, while the sum is 47.

The square root of 639962390 is about 25297.4779375336. The cubic root of 639962390 is about 861.7569947886.

The spelling of 639962390 in words is "six hundred thirty-nine million, nine hundred sixty-two thousand, three hundred ninety".