561557116381 has 4 divisors (see below), whose sum is σ = 564075309952. Its totient is φ = 559038922812.

The previous prime is 561557116363. The next prime is 561557116427. The reversal of 561557116381 is 183611755165.

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 a cyclic number.

It is not a de Polignac number, because 561557116381 - 2²¹ = 561555019229 is a prime.

It is a super-2 number, since 2×561557116381² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561557116361) 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 3 ways as a sum of consecutive naturals, for example, 1259096451 + ... + 1259096896.

It is an arithmetic number, because the mean of its divisors is an integer number (141018827488).

Almost surely, 2^561557116381 is an apocalyptic number.

It is an amenable number.

561557116381 is a deficient number, since it is larger than the sum of its proper divisors (2518193571).

561557116381 is a wasteful number, since it uses less digits than its factorization.

561557116381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2518193570.

The product of its digits is 756000, while the sum is 49.

The spelling of 561557116381 in words is "five hundred sixty-one billion, five hundred fifty-seven million, one hundred sixteen thousand, three hundred eighty-one".