561912153665 has 4 divisors (see below), whose sum is σ = 674294584404. Its totient is φ = 449529722928.

The previous prime is 561912153661. The next prime is 561912153667. The reversal of 561912153665 is 566351219165.

It is a happy number.

It is a Cunningham number, because it is equal to 749608²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 202287655696 + 359624497969 = 449764^2 + 599687^2 .

It is a cyclic number.

It is not a de Polignac number, because 561912153665 - 2² = 561912153661 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561912153661) 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, 56191215362 + ... + 56191215371.

It is an arithmetic number, because the mean of its divisors is an integer number (168573646101).

Almost surely, 2^561912153665 is an apocalyptic number.

It is an amenable number.

561912153665 is a deficient number, since it is larger than the sum of its proper divisors (112382430739).

561912153665 is a wasteful number, since it uses less digits than its factorization.

561912153665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112382430738.

The product of its digits is 1458000, while the sum is 50.

The spelling of 561912153665 in words is "five hundred sixty-one billion, nine hundred twelve million, one hundred fifty-three thousand, six hundred sixty-five".