638863770064 has 20 divisors (see below), whose sum is σ = 1333013828356. Its totient is φ = 294860201472.

The previous prime is 638863770049. The next prime is 638863770067. The reversal of 638863770064 is 460077368836.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 305366760000 + 333497010064 = 552600^2 + 577492^2 .

It is a junction number, because it is equal to n+sod(n) for n = 638863769990 and 638863770008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638863770067) 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, 1535730009 + ... + 1535730424.

Almost surely, 2^638863770064 is an apocalyptic number.

It is an amenable number.

638863770064 is an abundant number, since it is smaller than the sum of its proper divisors (694150058292).

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

638863770064 is a wasteful number, since it uses less digits than its factorization.

638863770064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3071460454 (or 3071460448 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 58.

The spelling of 638863770064 in words is "six hundred thirty-eight billion, eight hundred sixty-three million, seven hundred seventy thousand, sixty-four".