261868228 has 18 divisors (see below), whose sum is σ = 465038126. Its totient is φ = 129004128.

The previous prime is 261868219. The next prime is 261868247. The reversal of 261868228 is 822868162.

It can be written as a sum of positive squares in only one way, i.e., 229583104 + 32285124 = 15152^2 + 5682^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 276051 + ... + 276997.

Almost surely, 2^261868228 is an apocalyptic number.

It is an amenable number.

261868228 is a deficient number, since it is larger than the sum of its proper divisors (203169898).

261868228 is an frugal number, since it uses more digits than its factorization.

261868228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1971 (or 1022 counting only the distinct ones).

The product of its digits is 147456, while the sum is 43.

The square root of 261868228 is about 16182.3430936314. The cubic root of 261868228 is about 639.7754974289.

The spelling of 261868228 in words is "two hundred sixty-one million, eight hundred sixty-eight thousand, two hundred twenty-eight".