639451320 has 32 divisors (see below), whose sum is σ = 1918354320. Its totient is φ = 170520320.

The previous prime is 639451297. The next prime is 639451321. The reversal of 639451320 is 23154936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639451321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2664261 + ... + 2664500.

Almost surely, 2^639451320 is an apocalyptic number.

639451320 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

639451320 is an abundant number, since it is smaller than the sum of its proper divisors (1278903000).

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

639451320 is a wasteful number, since it uses less digits than its factorization.

639451320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5328775 (or 5328771 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 639451320 is about 25287.3747154583. The cubic root of 639451320 is about 861.5275357638.

The spelling of 639451320 in words is "six hundred thirty-nine million, four hundred fifty-one thousand, three hundred twenty".