501557156661 has 16 divisors (see below), whose sum is σ = 729550283328. Its totient is φ = 303968784000.

The previous prime is 501557156641. The next prime is 501557156699. The reversal of 501557156661 is 166651755105.

It is not a de Polignac number, because 501557156661 - 2⁵ = 501557156629 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 501557156661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (501557156641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2756475 + ... + 2932791.

It is an arithmetic number, because the mean of its divisors is an integer number (45596892708).

Almost surely, 2^501557156661 is an apocalyptic number.

It is an amenable number.

501557156661 is a deficient number, since it is larger than the sum of its proper divisors (227993126667).

501557156661 is a wasteful number, since it uses less digits than its factorization.

501557156661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262532.

The product of its (nonzero) digits is 945000, while the sum is 48.

The spelling of 501557156661 in words is "five hundred one billion, five hundred fifty-seven million, one hundred fifty-six thousand, six hundred sixty-one".