261525917 has 2 divisors, whose sum is σ = 261525918. Its totient is φ = 261525916.

The previous prime is 261525883. The next prime is 261525947. The reversal of 261525917 is 719525162.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209844196 + 51681721 = 14486^2 + 7189^2 .

It is a cyclic number.

It is not a de Polignac number, because 261525917 - 2²⁶ = 194417053 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261525947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130762958 + 130762959.

It is an arithmetic number, because the mean of its divisors is an integer number (130762959).

Almost surely, 2^261525917 is an apocalyptic number.

It is an amenable number.

261525917 is a deficient number, since it is larger than the sum of its proper divisors (1).

261525917 is an equidigital number, since it uses as much as digits as its factorization.

261525917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37800, while the sum is 38.

The square root of 261525917 is about 16171.7629527519. The cubic root of 261525917 is about 639.4966069261.

The spelling of 261525917 in words is "two hundred sixty-one million, five hundred twenty-five thousand, nine hundred seventeen".