501621138 has 18 divisors (see below), whose sum is σ = 1087051719. Its totient is φ = 167175372.

The previous prime is 501621067. The next prime is 501621143. The reversal of 501621138 is 831126105.

501621138 is a `hidden beast` number, since 5 + 0 + 1 + 621 + 1 + 38 = 666.

It can be written as a sum of positive squares in only one way, i.e., 250810569 + 250810569 = 15837^2 + 15837^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=15837.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 92383 + ... + 97661.

Almost surely, 2^501621138 is an apocalyptic number.

501621138 is an abundant number, since it is smaller than the sum of its proper divisors (585430581).

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

501621138 is an frugal number, since it uses more digits than its factorization.

501621138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10566 (or 5284 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 501621138 is about 22396.9001873027. The cubic root of 501621138 is about 794.5573992992.

The spelling of 501621138 in words is "five hundred one million, six hundred twenty-one thousand, one hundred thirty-eight".