639722465450 has 12 divisors (see below), whose sum is σ = 1189883785830. Its totient is φ = 255888986160.

The previous prime is 639722465449. The next prime is 639722465461. The reversal of 639722465450 is 54564227936.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 492519029209 + 147203436241 = 701797^2 + 383671^2 .

It is a junction number, because it is equal to n+sod(n) for n = 639722465392 and 639722465401.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6397224605 + ... + 6397224704.

Almost surely, 2^639722465450 is an apocalyptic number.

639722465450 is a deficient number, since it is larger than the sum of its proper divisors (550161320380).

639722465450 is a wasteful number, since it uses less digits than its factorization.

639722465450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12794449321 (or 12794449316 counting only the distinct ones).

The product of its (nonzero) digits is 10886400, while the sum is 53.

The spelling of 639722465450 in words is "six hundred thirty-nine billion, seven hundred twenty-two million, four hundred sixty-five thousand, four hundred fifty".