639067968 has 280 divisors, whose sum is σ = 2363321664. Its totient is φ = 165888000.

The previous prime is 639067967. The next prime is 639067993. The reversal of 639067968 is 869760936.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639067963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 398368 + ... + 399968.

Almost surely, 2^639067968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639067968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1181660832).

639067968 is an abundant number, since it is smaller than the sum of its proper divisors (1724253696).

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

639067968 is a wasteful number, since it uses less digits than its factorization.

639067968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1643 (or 1624 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 54.

The square root of 639067968 is about 25279.7936700441. The cubic root of 639067968 is about 861.3553390099.

The spelling of 639067968 in words is "six hundred thirty-nine million, sixty-seven thousand, nine hundred sixty-eight".