228187261 has 4 divisors (see below), whose sum is σ = 228217500. Its totient is φ = 228157024.

The previous prime is 228187247. The next prime is 228187291. The reversal of 228187261 is 162781822.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 16048036 + 212139225 = 4006^2 + 14565^2 .

It is a cyclic number.

It is not a de Polignac number, because 228187261 - 2⁵ = 228187229 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 228187261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228187241) 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, 6615 + ... + 22363.

It is an arithmetic number, because the mean of its divisors is an integer number (57054375).

Almost surely, 2^228187261 is an apocalyptic number.

It is an amenable number.

228187261 is a deficient number, since it is larger than the sum of its proper divisors (30239).

228187261 is a wasteful number, since it uses less digits than its factorization.

228187261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30238.

The product of its digits is 21504, while the sum is 37.

The square root of 228187261 is about 15105.8684291900. The cubic root of 228187261 is about 611.0786799673.

It can be divided in two parts, 228 and 187261, that added together give a square (187489 = 433²).

The spelling of 228187261 in words is "two hundred twenty-eight million, one hundred eighty-seven thousand, two hundred sixty-one".