561491951 has 2 divisors, whose sum is σ = 561491952. Its totient is φ = 561491950.

The previous prime is 561491921. The next prime is 561491981. The reversal of 561491951 is 159194165.

It is a balanced prime because it is at equal distance from previous prime (561491921) and next prime (561491981).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561491951 is a prime.

It is a super-2 number, since 2×561491951² = 630546422075572802, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 561491899 and 561491908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561491921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280745975 + 280745976.

It is an arithmetic number, because the mean of its divisors is an integer number (280745976).

Almost surely, 2^561491951 is an apocalyptic number.

561491951 is a deficient number, since it is larger than the sum of its proper divisors (1).

561491951 is an equidigital number, since it uses as much as digits as its factorization.

561491951 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48600, while the sum is 41.

The square root of 561491951 is about 23695.8213826826. The cubic root of 561491951 is about 824.9884055916.

The spelling of 561491951 in words is "five hundred sixty-one million, four hundred ninety-one thousand, nine hundred fifty-one".