25957721 has 4 divisors (see below), whose sum is σ = 26006244. Its totient is φ = 25909200.

The previous prime is 25957717. The next prime is 25957739. The reversal of 25957721 is 12775952.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8410000 + 17547721 = 2900^2 + 4189^2 .

It is a cyclic number.

It is not a de Polignac number, because 25957721 - 2² = 25957717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25959721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23450 + ... + 24531.

It is an arithmetic number, because the mean of its divisors is an integer number (6501561).

Almost surely, 2^25957721 is an apocalyptic number.

It is an amenable number.

25957721 is a deficient number, since it is larger than the sum of its proper divisors (48523).

25957721 is an equidigital number, since it uses as much as digits as its factorization.

25957721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48522.

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

The square root of 25957721 is about 5094.8720297962. The cubic root of 25957721 is about 296.0889410411.

The spelling of 25957721 in words is "twenty-five million, nine hundred fifty-seven thousand, seven hundred twenty-one".