639658272 has 144 divisors (see below), whose sum is σ = 1882258560. Its totient is φ = 189995520.

The previous prime is 639658259. The next prime is 639658277. The reversal of 639658272 is 272856936.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639658277) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 615129 + ... + 616167.

It is an arithmetic number, because the mean of its divisors is an integer number (13071240).

Almost surely, 2^639658272 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 639658272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (941129280).

639658272 is an abundant number, since it is smaller than the sum of its proper divisors (1242600288).

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

639658272 is a wasteful number, since it uses less digits than its factorization.

639658272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1127 (or 1108 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 48.

The square root of 639658272 is about 25291.4663869061. The cubic root of 639658272 is about 861.6204673183.

The spelling of 639658272 in words is "six hundred thirty-nine million, six hundred fifty-eight thousand, two hundred seventy-two".