561221122165 has 32 divisors (see below), whose sum is σ = 779200342272. Its totient is φ = 384014400000.

The previous prime is 561221122159. The next prime is 561221122183.

561221122165 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 561221122165 - 2³ = 561221122157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 561221122165.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3559336 + ... + 3713665.

It is an arithmetic number, because the mean of its divisors is an integer number (24350010696).

Almost surely, 2^561221122165 is an apocalyptic number.

561221122165 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

561221122165 is a deficient number, since it is larger than the sum of its proper divisors (217979220107).

561221122165 is a wasteful number, since it uses less digits than its factorization.

561221122165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7273101.

The product of its digits is 14400, while the sum is 34.

It can be divided in two parts, 561221 and 122165, that added together give a palindrome (683386).

The spelling of 561221122165 in words is "five hundred sixty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, one hundred sixty-five".