25804721 has 2 divisors, whose sum is σ = 25804722. Its totient is φ = 25804720.

The previous prime is 25804663. The next prime is 25804729. The reversal of 25804721 is 12740852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23658496 + 2146225 = 4864^2 + 1465^2 .

It is a cyclic number.

It is not a de Polignac number, because 25804721 - 2¹⁰ = 25803697 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (25804729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12902360 + 12902361.

It is an arithmetic number, because the mean of its divisors is an integer number (12902361).

Almost surely, 2^25804721 is an apocalyptic number.

It is an amenable number.

25804721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25804721 is an equidigital number, since it uses as much as digits as its factorization.

25804721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 25804721 is about 5079.8347414065. The cubic root of 25804721 is about 295.5060585124.

The spelling of 25804721 in words is "twenty-five million, eight hundred four thousand, seven hundred twenty-one".