228639261 has 4 divisors (see below), whose sum is σ = 304852352. Its totient is φ = 152426172.

The previous prime is 228639253. The next prime is 228639283. The reversal of 228639261 is 162936822.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 228639261 - 2³ = 228639253 is a prime.

It is a super-2 number, since 2×228639261² = 104551823341252242, 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 (228639211) 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, 38106541 + ... + 38106546.

It is an arithmetic number, because the mean of its divisors is an integer number (76213088).

Almost surely, 2^228639261 is an apocalyptic number.

It is an amenable number.

228639261 is a deficient number, since it is larger than the sum of its proper divisors (76213091).

228639261 is an equidigital number, since it uses as much as digits as its factorization.

228639261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76213090.

The product of its digits is 62208, while the sum is 39.

The square root of 228639261 is about 15120.8221006664. The cubic root of 228639261 is about 611.4818946914.

The spelling of 228639261 in words is "two hundred twenty-eight million, six hundred thirty-nine thousand, two hundred sixty-one".