261243925 has 12 divisors (see below), whose sum is σ = 327585060. Its totient is φ = 206645120.

The previous prime is 261243889. The next prime is 261243929. The reversal of 261243925 is 529342162.

It can be written as a sum of positive squares in 6 ways, for example, as 2452356 + 258791569 = 1566^2 + 16087^2 .

It is not a de Polignac number, because 261243925 - 2²⁷ = 127026197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261243929) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56482 + ... + 60931.

It is an arithmetic number, because the mean of its divisors is an integer number (27298755).

Almost surely, 2^261243925 is an apocalyptic number.

261243925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261243925 is a deficient number, since it is larger than the sum of its proper divisors (66341135).

261243925 is a wasteful number, since it uses less digits than its factorization.

261243925 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117512 (or 117507 counting only the distinct ones).

The product of its digits is 25920, while the sum is 34.

The square root of 261243925 is about 16163.0419476038. The cubic root of 261243925 is about 639.2666771570.

The spelling of 261243925 in words is "two hundred sixty-one million, two hundred forty-three thousand, nine hundred twenty-five".