561500761 has 2 divisors, whose sum is σ = 561500762. Its totient is φ = 561500760.

The previous prime is 561500759. The next prime is 561500777. The reversal of 561500761 is 167005165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 473497600 + 88003161 = 21760^2 + 9381^2 .

It is a cyclic number.

It is not a de Polignac number, because 561500761 - 2¹ = 561500759 is a prime.

Together with 561500759, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (561500161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280750380 + 280750381.

It is an arithmetic number, because the mean of its divisors is an integer number (280750381).

Almost surely, 2^561500761 is an apocalyptic number.

It is an amenable number.

561500761 is a deficient number, since it is larger than the sum of its proper divisors (1).

561500761 is an equidigital number, since it uses as much as digits as its factorization.

561500761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 561500761 is about 23696.0072797085. The cubic root of 561500761 is about 824.9927203520.

The spelling of 561500761 in words is "five hundred sixty-one million, five hundred thousand, seven hundred sixty-one".