50561156721 has 4 divisors (see below), whose sum is σ = 67414875632. Its totient is φ = 33707437812.

The previous prime is 50561156683. The next prime is 50561156741. The reversal of 50561156721 is 12765116505.

It is a happy number.

50561156721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 50561156721 - 2³⁰ = 49487414897 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 50561156721.

It is not an unprimeable number, because it can be changed into a prime (50561156741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8426859451 + ... + 8426859456.

It is an arithmetic number, because the mean of its divisors is an integer number (16853718908).

Almost surely, 2^50561156721 is an apocalyptic number.

It is an amenable number.

50561156721 is a deficient number, since it is larger than the sum of its proper divisors (16853718911).

50561156721 is a wasteful number, since it uses less digits than its factorization.

50561156721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16853718910.

The product of its (nonzero) digits is 63000, while the sum is 39.

The spelling of 50561156721 in words is "fifty billion, five hundred sixty-one million, one hundred fifty-six thousand, seven hundred twenty-one".