25209009 has 32 divisors (see below), whose sum is σ = 43223040. Its totient is φ = 14222736.

The previous prime is 25209001. The next prime is 25209013. The reversal of 25209009 is 90090252.

It is not a de Polignac number, because 25209009 - 2³ = 25209001 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (25209001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14884 + ... + 16490.

It is an arithmetic number, because the mean of its divisors is an integer number (1350720).

Almost surely, 2^25209009 is an apocalyptic number.

It is an amenable number.

25209009 is a deficient number, since it is larger than the sum of its proper divisors (18014031).

25209009 is a wasteful number, since it uses less digits than its factorization.

25209009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1706 (or 1700 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 25209009 is about 5020.8573968995. The cubic root of 25209009 is about 293.2143748299.

It can be divided in two parts, 25 and 209009, that multiplied together give a palindrome (5225225).

The spelling of 25209009 in words is "twenty-five million, two hundred nine thousand, nine".