639950400 has 252 divisors, whose sum is σ = 2395270800. Its totient is φ = 161602560.

The previous prime is 639950393. The next prime is 639950401. The reversal of 639950400 is 4059936.

639950400 is a `hidden beast` number, since 63 + 99 + 504 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (639950401) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 272431 + ... + 274769.

Almost surely, 2^639950400 is an apocalyptic number.

639950400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639950400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1197635400).

639950400 is an abundant number, since it is smaller than the sum of its proper divisors (1755320400).

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

639950400 is a wasteful number, since it uses less digits than its factorization.

639950400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2386 (or 2368 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 36.

The square root of 639950400 is about 25297.2409562782. The cubic root of 639950400 is about 861.7516129458.

The spelling of 639950400 in words is "six hundred thirty-nine million, nine hundred fifty thousand, four hundred".