639997152 has 48 divisors (see below), whose sum is σ = 1681384320. Its totient is φ = 213155712.

The previous prime is 639997151. The next prime is 639997187. The reversal of 639997152 is 251799936.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×639997152² = 819192709136222208, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 639997095 and 639997104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639997151) 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, 169299 + ... + 173037.

It is an arithmetic number, because the mean of its divisors is an integer number (35028840).

Almost surely, 2^639997152 is an apocalyptic number.

It is an amenable number.

639997152 is an abundant number, since it is smaller than the sum of its proper divisors (1041387168).

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

639997152 is a wasteful number, since it uses less digits than its factorization.

639997152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5535 (or 5527 counting only the distinct ones).

The product of its digits is 918540, while the sum is 51.

The square root of 639997152 is about 25298.1649927421. The cubic root of 639997152 is about 861.7725977129.

The spelling of 639997152 in words is "six hundred thirty-nine million, nine hundred ninety-seven thousand, one hundred fifty-two".