25739561 has 2 divisors, whose sum is σ = 25739562. Its totient is φ = 25739560.

The previous prime is 25739557. The next prime is 25739563. The reversal of 25739561 is 16593752.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20070400 + 5669161 = 4480^2 + 2381^2 .

It is a cyclic number.

It is not a de Polignac number, because 25739561 - 2² = 25739557 is a prime.

Together with 25739563, 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 (25739563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12869780 + 12869781.

It is an arithmetic number, because the mean of its divisors is an integer number (12869781).

Almost surely, 2^25739561 is an apocalyptic number.

It is an amenable number.

25739561 is a deficient number, since it is larger than the sum of its proper divisors (1).

25739561 is an equidigital number, since it uses as much as digits as its factorization.

25739561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 56700, while the sum is 38.

The square root of 25739561 is about 5073.4170930449. The cubic root of 25739561 is about 295.2571195069.

The spelling of 25739561 in words is "twenty-five million, seven hundred thirty-nine thousand, five hundred sixty-one".