261905925 has 24 divisors (see below), whose sum is σ = 433563520. Its totient is φ = 139507200.

The previous prime is 261905923. The next prime is 261905929. The reversal of 261905925 is 529509162.

It is not a de Polignac number, because 261905925 - 2¹ = 261905923 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261905921) 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, 76245 + ... + 79605.

Almost surely, 2^261905925 is an apocalyptic number.

261905925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261905925 is a deficient number, since it is larger than the sum of its proper divisors (171657595).

261905925 is a wasteful number, since it uses less digits than its factorization.

261905925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4413 (or 4408 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 39.

The square root of 261905925 is about 16183.5078088775. The cubic root of 261905925 is about 639.8061953871.

The spelling of 261905925 in words is "two hundred sixty-one million, nine hundred five thousand, nine hundred twenty-five".