639964080 has 480 divisors, whose sum is σ = 2664829440. Its totient is φ = 134369280.

The previous prime is 639964033. The next prime is 639964081. The reversal of 639964080 is 80469936.

639964080 is a `hidden beast` number, since 639 + 9 + 6 + 4 + 0 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (639964081) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3926079 + ... + 3926241.

It is an arithmetic number, because the mean of its divisors is an integer number (5551728).

Almost surely, 2^639964080 is an apocalyptic number.

639964080 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 639964080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1332414720).

639964080 is an abundant number, since it is smaller than the sum of its proper divisors (2024865360).

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

639964080 is a wasteful number, since it uses less digits than its factorization.

639964080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249 (or 240 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 639964080 is about 25297.5113400508. The cubic root of 639964080 is about 861.7577533582.

The spelling of 639964080 in words is "six hundred thirty-nine million, nine hundred sixty-four thousand, eighty".