261228169 has 16 divisors (see below), whose sum is σ = 280874880. Its totient is φ = 242213760.

The previous prime is 261228161. The next prime is 261228173. The reversal of 261228169 is 961822162.

It is a cyclic number.

It is not a de Polignac number, because 261228169 - 2³ = 261228161 is a prime.

It is a super-2 number, since 2×261228169² = 136480312558185122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261228161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 304389 + ... + 305245.

It is an arithmetic number, because the mean of its divisors is an integer number (17554680).

Almost surely, 2^261228169 is an apocalyptic number.

It is an amenable number.

261228169 is a deficient number, since it is larger than the sum of its proper divisors (19646711).

261228169 is a wasteful number, since it uses less digits than its factorization.

261228169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1200.

The product of its digits is 20736, while the sum is 37.

The square root of 261228169 is about 16162.5545320039. The cubic root of 261228169 is about 639.2538251985.

The spelling of 261228169 in words is "two hundred sixty-one million, two hundred twenty-eight thousand, one hundred sixty-nine".