639997153 has 4 divisors (see below), whose sum is σ = 640053700. Its totient is φ = 639940608.

The previous prime is 639997151. The next prime is 639997187. The reversal of 639997153 is 351799936.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 340291809 + 299705344 = 18447^2 + 17312^2 .

It is a cyclic number.

It is not a de Polignac number, because 639997153 - 2¹ = 639997151 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639997153.

It is not an unprimeable number, because it can be changed into a prime (639997151) 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 3 ways as a sum of consecutive naturals, for example, 4800 + ... + 36097.

It is an arithmetic number, because the mean of its divisors is an integer number (160013425).

Almost surely, 2^639997153 is an apocalyptic number.

It is an amenable number.

639997153 is a deficient number, since it is larger than the sum of its proper divisors (56547).

639997153 is a wasteful number, since it uses less digits than its factorization.

639997153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56546.

The product of its digits is 1377810, while the sum is 52.

The square root of 639997153 is about 25298.1650125063. The cubic root of 639997153 is about 861.7725981618.

The spelling of 639997153 in words is "six hundred thirty-nine million, nine hundred ninety-seven thousand, one hundred fifty-three".