228278261 has 8 divisors (see below), whose sum is σ = 246267864. Its totient is φ = 210795520.

The previous prime is 228278249. The next prime is 228278279. The reversal of 228278261 is 162872822.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 53377636 + 174900625 = 7306^2 + 13225^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 228278261 - 2¹⁰ = 228277237 is a prime.

It is a super-2 number, since 2×228278261² = 104221928890368242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228278231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125780 + ... + 127581.

It is an arithmetic number, because the mean of its divisors is an integer number (30783483).

Almost surely, 2^228278261 is an apocalyptic number.

It is an amenable number.

228278261 is a deficient number, since it is larger than the sum of its proper divisors (17989603).

228278261 is a wasteful number, since it uses less digits than its factorization.

228278261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253431.

The product of its digits is 43008, while the sum is 38.

The square root of 228278261 is about 15108.8802033771. The cubic root of 228278261 is about 611.1599009335.

The spelling of 228278261 in words is "two hundred twenty-eight million, two hundred seventy-eight thousand, two hundred sixty-one".