639491088 has 40 divisors (see below), whose sum is σ = 1680026400. Its totient is φ = 209549824.

The previous prime is 639491087. The next prime is 639491117. The reversal of 639491088 is 880194936.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (639491087) 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 7 ways as a sum of consecutive naturals, for example, 110073 + ... + 115736.

It is an arithmetic number, because the mean of its divisors is an integer number (42000660).

Almost surely, 2^639491088 is an apocalyptic number.

It is an amenable number.

639491088 is an abundant number, since it is smaller than the sum of its proper divisors (1040535312).

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

639491088 is a wasteful number, since it uses less digits than its factorization.

639491088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225879 (or 225873 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 48.

The square root of 639491088 is about 25288.1610244794. The cubic root of 639491088 is about 861.5453950940.

The spelling of 639491088 in words is "six hundred thirty-nine million, four hundred ninety-one thousand, eighty-eight".