25564961 has 2 divisors, whose sum is σ = 25564962. Its totient is φ = 25564960.

The previous prime is 25564951. The next prime is 25564963. The reversal of 25564961 is 16946552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25150225 + 414736 = 5015^2 + 644^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25564961 is a prime.

Together with 25564963, 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 (25564963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12782480 + 12782481.

It is an arithmetic number, because the mean of its divisors is an integer number (12782481).

Almost surely, 2^25564961 is an apocalyptic number.

It is an amenable number.

25564961 is a deficient number, since it is larger than the sum of its proper divisors (1).

25564961 is an equidigital number, since it uses as much as digits as its factorization.

25564961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64800, while the sum is 38.

The square root of 25564961 is about 5056.1804754182. The cubic root of 25564961 is about 294.5879951852.

The spelling of 25564961 in words is "twenty-five million, five hundred sixty-four thousand, nine hundred sixty-one".