561931 has 2 divisors, whose sum is σ = 561932. Its totient is φ = 561930.

The previous prime is 561923. The next prime is 561943. The reversal of 561931 is 139165.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 561931 - 2³ = 561923 is a prime.

It is a super-2 number, since 2×561931² = 631532897522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 561896 and 561905.

It is not a weakly prime, because it can be changed into another prime (561961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280965 + 280966.

It is an arithmetic number, because the mean of its divisors is an integer number (280966).

2⁵⁶¹⁹³¹ is an apocalyptic number.

561931 is a deficient number, since it is larger than the sum of its proper divisors (1).

561931 is an equidigital number, since it uses as much as digits as its factorization.

561931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 810, while the sum is 25.

The square root of 561931 is about 749.6205706889. The cubic root of 561931 is about 82.5203378081.

The spelling of 561931 in words is "five hundred sixty-one thousand, nine hundred thirty-one".