25056721 has 2 divisors, whose sum is σ = 25056722. Its totient is φ = 25056720.

The previous prime is 25056701. The next prime is 25056751. The reversal of 25056721 is 12765052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22043025 + 3013696 = 4695^2 + 1736^2 .

It is a cyclic number.

It is not a de Polignac number, because 25056721 - 2⁹ = 25056209 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a self number, because there is not a number n which added to its sum of digits gives 25056721.

It is not a weakly prime, because it can be changed into another prime (25056701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12528360 + 12528361.

It is an arithmetic number, because the mean of its divisors is an integer number (12528361).

Almost surely, 2^25056721 is an apocalyptic number.

It is an amenable number.

25056721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25056721 is an equidigital number, since it uses as much as digits as its factorization.

25056721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 25056721 is about 5005.6688863727. The cubic root of 25056721 is about 292.6227444033.

The spelling of 25056721 in words is "twenty-five million, fifty-six thousand, seven hundred twenty-one".