501415565661 has 6 divisors (see below), whose sum is σ = 724266928190. Its totient is φ = 334277043768.

The previous prime is 501415565659. The next prime is 501415565681. The reversal of 501415565661 is 166565514105.

501415565661 is a `hidden beast` number, since 5 + 0 + 1 + 41 + 556 + 56 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 496221624900 + 5193940761 = 704430^2 + 72069^2 .

It is not a de Polignac number, because 501415565661 - 2¹ = 501415565659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501415565621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 27856420306 + ... + 27856420323.

Almost surely, 2^501415565661 is an apocalyptic number.

It is an amenable number.

501415565661 is a deficient number, since it is larger than the sum of its proper divisors (222851362529).

501415565661 is a wasteful number, since it uses less digits than its factorization.

501415565661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55712840635 (or 55712840632 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 45.

The spelling of 501415565661 in words is "five hundred one billion, four hundred fifteen million, five hundred sixty-five thousand, six hundred sixty-one".