561557263 has 2 divisors, whose sum is σ = 561557264. Its totient is φ = 561557262.

The previous prime is 561557237. The next prime is 561557317. The reversal of 561557263 is 362755165.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561557263 is a prime.

It is equal to p_29419339 and since 561557263 and 29419339 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561557063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280778631 + 280778632.

It is an arithmetic number, because the mean of its divisors is an integer number (280778632).

Almost surely, 2^561557263 is an apocalyptic number.

561557263 is a deficient number, since it is larger than the sum of its proper divisors (1).

561557263 is an equidigital number, since it uses as much as digits as its factorization.

561557263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 189000, while the sum is 40.

The square root of 561557263 is about 23697.1994758874. The cubic root of 561557263 is about 825.0203915376.

The spelling of 561557263 in words is "five hundred sixty-one million, five hundred fifty-seven thousand, two hundred sixty-three".