638407044244 has 12 divisors (see below), whose sum is σ = 1117311126484. Its totient is φ = 319175293824.

The previous prime is 638407044241. The next prime is 638407044263. The reversal of 638407044244 is 442440704836.

It can be written as a sum of positive squares in 2 ways, for example, as 593420634244 + 44986410000 = 770338^2 + 212100^2 .

It is a junction number, because it is equal to n+sod(n) for n = 638407044194 and 638407044203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638407044241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7006149 + ... + 7096684.

Almost surely, 2^638407044244 is an apocalyptic number.

It is an amenable number.

638407044244 is a deficient number, since it is larger than the sum of its proper divisors (478904082240).

638407044244 is a wasteful number, since it uses less digits than its factorization.

638407044244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14114154 (or 14114152 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 46.

The spelling of 638407044244 in words is "six hundred thirty-eight billion, four hundred seven million, forty-four thousand, two hundred forty-four".