561326666137 has 2 divisors, whose sum is σ = 561326666138. Its totient is φ = 561326666136.

The previous prime is 561326666107. The next prime is 561326666161. The reversal of 561326666137 is 731666623165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 543494802841 + 17831863296 = 737221^2 + 133536^2 .

It is a cyclic number.

It is not a de Polignac number, because 561326666137 - 2¹¹ = 561326664089 is a prime.

It is a super-2 number, since 2×561326666137² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (561326666107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280663333068 + 280663333069.

It is an arithmetic number, because the mean of its divisors is an integer number (280663333069).

Almost surely, 2^561326666137 is an apocalyptic number.

It is an amenable number.

561326666137 is a deficient number, since it is larger than the sum of its proper divisors (1).

561326666137 is an equidigital number, since it uses as much as digits as its factorization.

561326666137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4898880, while the sum is 52.

The spelling of 561326666137 in words is "five hundred sixty-one billion, three hundred twenty-six million, six hundred sixty-six thousand, one hundred thirty-seven".