261285269 has 4 divisors (see below), whose sum is σ = 298611744. Its totient is φ = 223958796.

The previous prime is 261285263. The next prime is 261285293. The reversal of 261285269 is 962582162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261285269 is a prime.

It is a super-2 number, since 2×261285269² = 136539983592804722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261285263) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18663227 + ... + 18663240.

It is an arithmetic number, because the mean of its divisors is an integer number (74652936).

Almost surely, 2^261285269 is an apocalyptic number.

It is an amenable number.

261285269 is a deficient number, since it is larger than the sum of its proper divisors (37326475).

261285269 is an equidigital number, since it uses as much as digits as its factorization.

261285269 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37326474.

The product of its digits is 103680, while the sum is 41.

The square root of 261285269 is about 16164.3208641749. The cubic root of 261285269 is about 639.3003984482.

The spelling of 261285269 in words is "two hundred sixty-one million, two hundred eighty-five thousand, two hundred sixty-nine".