639965088 has 216 divisors, whose sum is σ = 2142749700. Its totient is φ = 180633600.

The previous prime is 639965083. The next prime is 639965093. The reversal of 639965088 is 880569936.

It is an interprime number because it is at equal distance from previous prime (639965083) and next prime (639965093).

It can be written as a sum of positive squares in 2 ways, for example, as 565107984 + 74857104 = 23772^2 + 8652^2 .

It is not an unprimeable number, because it can be changed into a prime (639965083) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1425088 + ... + 1425536.

Almost surely, 2^639965088 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 639965088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1071374850).

639965088 is an abundant number, since it is smaller than the sum of its proper divisors (1502784612).

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

639965088 is a wasteful number, since it uses less digits than its factorization.

639965088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580 (or 562 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 54.

The square root of 639965088 is about 25297.5312629513. The cubic root of 639965088 is about 861.7582058062.

The spelling of 639965088 in words is "six hundred thirty-nine million, nine hundred sixty-five thousand, eighty-eight".