261228 has 24 divisors (see below), whose sum is σ = 665280. Its totient is φ = 79120.

The previous prime is 261223. The next prime is 261229. The reversal of 261228 is 822162.

It is a nialpdrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (261223) by changing a digit.

261228 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 858 + ... + 1121.

It is an arithmetic number, because the mean of its divisors is an integer number (27720).

2²⁶¹²²⁸ is an apocalyptic number.

It is an amenable number.

261228 is an abundant number, since it is smaller than the sum of its proper divisors (404052).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261228 is a wasteful number, since it uses less digits than its factorization.

261228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1997 (or 1995 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 261228 is about 511.1046859500. The cubic root of 261228 is about 63.9253687345.

The spelling of 261228 in words is "two hundred sixty-one thousand, two hundred twenty-eight".