25999409 has 4 divisors (see below), whose sum is σ = 27528804. Its totient is φ = 24470016.

The previous prime is 25999403. The next prime is 25999411. The reversal of 25999409 is 90499952.

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 24039409 + 1960000 = 4903^2 + 1400^2 .

It is a cyclic number.

It is not a de Polignac number, because 25999409 - 2²⁴ = 9222193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25999403) 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, 764672 + ... + 764705.

It is an arithmetic number, because the mean of its divisors is an integer number (6882201).

Almost surely, 2^25999409 is an apocalyptic number.

It is an amenable number.

25999409 is a deficient number, since it is larger than the sum of its proper divisors (1529395).

25999409 is a wasteful number, since it uses less digits than its factorization.

25999409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1529394.

The product of its (nonzero) digits is 262440, while the sum is 47.

The square root of 25999409 is about 5098.9615609455. The cubic root of 25999409 is about 296.2473621632.

The spelling of 25999409 in words is "twenty-five million, nine hundred ninety-nine thousand, four hundred nine".