561557237 has 2 divisors, whose sum is σ = 561557238. Its totient is φ = 561557236.

The previous prime is 561557173. The next prime is 561557263. The reversal of 561557237 is 732755165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 560316241 + 1240996 = 23671^2 + 1114^2 .

It is a cyclic number.

It is not a de Polignac number, because 561557237 - 2⁶ = 561557173 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 561557194 and 561557203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561557837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280778618 + 280778619.

It is an arithmetic number, because the mean of its divisors is an integer number (280778619).

Almost surely, 2^561557237 is an apocalyptic number.

It is an amenable number.

561557237 is a deficient number, since it is larger than the sum of its proper divisors (1).

561557237 is an equidigital number, since it uses as much as digits as its factorization.

561557237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 220500, while the sum is 41.

The square root of 561557237 is about 23697.1989272994. The cubic root of 561557237 is about 825.0203788048.

The spelling of 561557237 in words is "five hundred sixty-one million, five hundred fifty-seven thousand, two hundred thirty-seven".