12564781 has 2 divisors, whose sum is σ = 12564782. Its totient is φ = 12564780.

The previous prime is 12564767. The next prime is 12564787. The reversal of 12564781 is 18746521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12489156 + 75625 = 3534^2 + 275^2 .

It is a cyclic number.

It is not a de Polignac number, because 12564781 - 2⁵ = 12564749 is a prime.

It is a super-2 number, since 2×12564781² = 315747443155922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12564787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6282390 + 6282391.

It is an arithmetic number, because the mean of its divisors is an integer number (6282391).

Almost surely, 2^12564781 is an apocalyptic number.

It is an amenable number.

12564781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12564781 is an equidigital number, since it uses as much as digits as its factorization.

12564781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13440, while the sum is 34.

The square root of 12564781 is about 3544.6834837542. The cubic root of 12564781 is about 232.4796667769.

The spelling of 12564781 in words is "twelve million, five hundred sixty-four thousand, seven hundred eighty-one".