25971409 has 4 divisors (see below), whose sum is σ = 26604900. Its totient is φ = 25337920.

The previous prime is 25971391. The next prime is 25971419. The reversal of 25971409 is 90417952.

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 6390784 + 19580625 = 2528^2 + 4425^2 .

It is a cyclic number.

It is not a de Polignac number, because 25971409 - 2⁵ = 25971377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25971419) 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, 316684 + ... + 316765.

It is an arithmetic number, because the mean of its divisors is an integer number (6651225).

Almost surely, 2^25971409 is an apocalyptic number.

It is an amenable number.

25971409 is a deficient number, since it is larger than the sum of its proper divisors (633491).

25971409 is an equidigital number, since it uses as much as digits as its factorization.

25971409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 633490.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 25971409 is about 5096.2151642175. The cubic root of 25971409 is about 296.1409763392.

The spelling of 25971409 in words is "twenty-five million, nine hundred seventy-one thousand, four hundred nine".