25509649 has 4 divisors (see below), whose sum is σ = 27828720. Its totient is φ = 23190580.

The previous prime is 25509643. The next prime is 25509709. The reversal of 25509649 is 94690552.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25509649 - 2³ = 25509641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25509641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1159519 + ... + 1159540.

It is an arithmetic number, because the mean of its divisors is an integer number (6957180).

Almost surely, 2^25509649 is an apocalyptic number.

It is an amenable number.

25509649 is a deficient number, since it is larger than the sum of its proper divisors (2319071).

25509649 is a wasteful number, since it uses less digits than its factorization.

25509649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2319070.

The product of its (nonzero) digits is 97200, while the sum is 40.

The square root of 25509649 is about 5050.7077721840. The cubic root of 25509649 is about 294.3753862596.

The spelling of 25509649 in words is "twenty-five million, five hundred nine thousand, six hundred forty-nine".