25864921 has 2 divisors, whose sum is σ = 25864922. Its totient is φ = 25864920.

The previous prime is 25864859. The next prime is 25864931. The reversal of 25864921 is 12946852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 4888521 = 4580^2 + 2211^2 .

It is a cyclic number.

It is not a de Polignac number, because 25864921 - 2⁹ = 25864409 is a prime.

It is not a weakly prime, because it can be changed into another prime (25864931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12932460 + 12932461.

It is an arithmetic number, because the mean of its divisors is an integer number (12932461).

Almost surely, 2^25864921 is an apocalyptic number.

It is an amenable number.

25864921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25864921 is an equidigital number, since it uses as much as digits as its factorization.

25864921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 37.

The square root of 25864921 is about 5085.7566791973. The cubic root of 25864921 is about 295.7356760426.

The spelling of 25864921 in words is "twenty-five million, eight hundred sixty-four thousand, nine hundred twenty-one".