12561911 has 2 divisors, whose sum is σ = 12561912. Its totient is φ = 12561910.

The previous prime is 12561889. The next prime is 12561917. The reversal of 12561911 is 11916521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12561911 - 2¹⁰ = 12560887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12561917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6280955 + 6280956.

It is an arithmetic number, because the mean of its divisors is an integer number (6280956).

Almost surely, 2^12561911 is an apocalyptic number.

12561911 is a deficient number, since it is larger than the sum of its proper divisors (1).

12561911 is an equidigital number, since it uses as much as digits as its factorization.

12561911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 26.

The square root of 12561911 is about 3544.2786290020. The cubic root of 12561911 is about 232.4619647188.

The spelling of 12561911 in words is "twelve million, five hundred sixty-one thousand, nine hundred eleven".