25531009 has 6 divisors (see below), whose sum is σ = 29699394. Its totient is φ = 21883680.

The previous prime is 25530997. The next prime is 25531013. The reversal of 25531009 is 90013552.

It can be written as a sum of positive squares in only one way, i.e., 14288400 + 11242609 = 3780^2 + 3353^2 .

It is not a de Polignac number, because 25531009 - 2⁵ = 25530977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25531019) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 260472 + ... + 260569.

It is an arithmetic number, because the mean of its divisors is an integer number (4949899).

Almost surely, 2^25531009 is an apocalyptic number.

It is an amenable number.

25531009 is a deficient number, since it is larger than the sum of its proper divisors (4168385).

25531009 is an equidigital number, since it uses as much as digits as its factorization.

25531009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521055 (or 521048 counting only the distinct ones).

The product of its (nonzero) digits is 1350, while the sum is 25.

The square root of 25531009 is about 5052.8218848481. The cubic root of 25531009 is about 294.4575264733.

The spelling of 25531009 in words is "twenty-five million, five hundred thirty-one thousand, nine".