639949275 has 192 divisors, whose sum is σ = 1474191360. Its totient is φ = 265420800.

The previous prime is 639949273. The next prime is 639949291. The reversal of 639949275 is 572949936.

639949275 is a `hidden beast` number, since 63 + 99 + 492 + 7 + 5 = 666.

It is not a de Polignac number, because 639949275 - 2¹ = 639949273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639949273) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2489947 + ... + 2490203.

It is an arithmetic number, because the mean of its divisors is an integer number (7678080).

Almost surely, 2^639949275 is an apocalyptic number.

639949275 is an abundant number, since it is smaller than the sum of its proper divisors (834242085).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639949275 is a wasteful number, since it uses less digits than its factorization.

639949275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331 (or 320 counting only the distinct ones).

The product of its digits is 3674160, while the sum is 54.

The square root of 639949275 is about 25297.2187206420. The cubic root of 639949275 is about 861.7511079738.

The spelling of 639949275 in words is "six hundred thirty-nine million, nine hundred forty-nine thousand, two hundred seventy-five".