261656525 has 12 divisors (see below), whose sum is σ = 349412532. Its totient is φ = 193223040.

The previous prime is 261656501. The next prime is 261656557. The reversal of 261656525 is 525656162.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 15888196 + 245768329 = 3986^2 + 15677^2 .

It is a de Polignac number, because none of the positive numbers 2^k-261656525 is a prime.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 402224 + ... + 402873.

It is an arithmetic number, because the mean of its divisors is an integer number (29117711).

Almost surely, 2^261656525 is an apocalyptic number.

261656525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261656525 is a deficient number, since it is larger than the sum of its proper divisors (87756007).

261656525 is a wasteful number, since it uses less digits than its factorization.

261656525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805120 (or 805115 counting only the distinct ones).

The product of its digits is 108000, while the sum is 38.

The square root of 261656525 is about 16175.8005984248. The cubic root of 261656525 is about 639.6030456729.

The spelling of 261656525 in words is "two hundred sixty-one million, six hundred fifty-six thousand, five hundred twenty-five".