63138640 has 40 divisors (see below), whose sum is σ = 147131208. Its totient is φ = 25198080.

The previous prime is 63138631. The next prime is 63138671. The reversal of 63138640 is 4683136.

63138640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 602176 + 62536464 = 776^2 + 7908^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×63138640² = 7972975722099200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61330 + ... + 62350.

Almost surely, 2^63138640 is an apocalyptic number.

It is an amenable number.

63138640 is an abundant number, since it is smaller than the sum of its proper divisors (83992568).

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

63138640 is a wasteful number, since it uses less digits than its factorization.

63138640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1807 (or 1801 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 63138640 is about 7945.9826327522. The cubic root of 63138640 is about 398.1973886841.

The spelling of 63138640 in words is "sixty-three million, one hundred thirty-eight thousand, six hundred forty".