639553320000 has 1400 divisors, whose sum is σ = 2739827424576. Its totient is φ = 144446976000.

The previous prime is 639553319957. The next prime is 639553320013. The reversal of 639553320000 is 23355936.

It is a tau number, because it is divible by the number of its divisors (1400).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 199 ways as a sum of consecutive naturals, for example, 3696839914 + ... + 3696840086.

Almost surely, 2^639553320000 is an apocalyptic number.

639553320000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639553320000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1369913712288).

639553320000 is an abundant number, since it is smaller than the sum of its proper divisors (2100274104576).

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

639553320000 is a wasteful number, since it uses less digits than its factorization.

639553320000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 387 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 72900, while the sum is 36.

Adding to 639553320000 its reverse (23355936), we get a palindrome (639576675936).

The spelling of 639553320000 in words is "six hundred thirty-nine billion, five hundred fifty-three million, three hundred twenty thousand".