25577921 has 2 divisors, whose sum is σ = 25577922. Its totient is φ = 25577920.

The previous prime is 25577873. The next prime is 25577941. The reversal of 25577921 is 12977552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18395521 + 7182400 = 4289^2 + 2680^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25577921 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (25577941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12788960 + 12788961.

It is an arithmetic number, because the mean of its divisors is an integer number (12788961).

Almost surely, 2^25577921 is an apocalyptic number.

It is an amenable number.

25577921 is a deficient number, since it is larger than the sum of its proper divisors (1).

25577921 is an equidigital number, since it uses as much as digits as its factorization.

25577921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 44100, while the sum is 38.

The square root of 25577921 is about 5057.4619128571. The cubic root of 25577921 is about 294.6377666342.

The spelling of 25577921 in words is "twenty-five million, five hundred seventy-seven thousand, nine hundred twenty-one".