638615532548 has 36 divisors (see below), whose sum is σ = 1313441263260. Its totient is φ = 270870792192.

The previous prime is 638615532517. The next prime is 638615532587. The reversal of 638615532548 is 845235516836.

It can be written as a sum of positive squares in 2 ways, for example, as 502961803204 + 135653729344 = 709198^2 + 368312^2 .

It is a junction number, because it is equal to n+sod(n) for n = 638615532493 and 638615532502.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16776053 + ... + 16814076.

It is an arithmetic number, because the mean of its divisors is an integer number (36484479535).

Almost surely, 2^638615532548 is an apocalyptic number.

It is an amenable number.

638615532548 is an abundant number, since it is smaller than the sum of its proper divisors (674825730712).

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

638615532548 is a wasteful number, since it uses less digits than its factorization.

638615532548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33590244 (or 33590235 counting only the distinct ones).

The product of its digits is 20736000, while the sum is 56.

The spelling of 638615532548 in words is "six hundred thirty-eight billion, six hundred fifteen million, five hundred thirty-two thousand, five hundred forty-eight".