638634508722 has 48 divisors (see below), whose sum is σ = 1587393624960. Its totient is φ = 181773202176.

The previous prime is 638634508703. The next prime is 638634508739. The reversal of 638634508722 is 227805436836.

638634508722 is a `hidden beast` number, since 6 + 3 + 8 + 63 + 4 + 508 + 72 + 2 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9602847 + ... + 9669122.

It is an arithmetic number, because the mean of its divisors is an integer number (33070700520).

Almost surely, 2^638634508722 is an apocalyptic number.

638634508722 is an abundant number, since it is smaller than the sum of its proper divisors (948759116238).

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

638634508722 is a wasteful number, since it uses less digits than its factorization.

638634508722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19272247 (or 19272244 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 54.

The spelling of 638634508722 in words is "six hundred thirty-eight billion, six hundred thirty-four million, five hundred eight thousand, seven hundred twenty-two".