25209961 has 24 divisors (see below), whose sum is σ = 30800520. Its totient is φ = 20547072.

The previous prime is 25209937. The next prime is 25209967. The reversal of 25209961 is 16990252.

It can be written as a sum of positive squares in 4 ways, for example, as 19600 + 25190361 = 140^2 + 5019^2 .

It is a de Polignac number, because none of the positive numbers 2^k-25209961 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25209967) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 160495 + ... + 160651.

It is an arithmetic number, because the mean of its divisors is an integer number (1283355).

Almost surely, 2^25209961 is an apocalyptic number.

It is an amenable number.

25209961 is a deficient number, since it is larger than the sum of its proper divisors (5590559).

25209961 is a wasteful number, since it uses less digits than its factorization.

25209961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313 (or 306 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 25209961 is about 5020.9522005293. The cubic root of 25209961 is about 293.2180657931.

The spelling of 25209961 in words is "twenty-five million, two hundred nine thousand, nine hundred sixty-one".