228805561 has 4 divisors (see below), whose sum is σ = 231376500. Its totient is φ = 226234624.

The previous prime is 228805487. The next prime is 228805573. The reversal of 228805561 is 165508822.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 118135161 + 110670400 = 10869^2 + 10520^2 .

It is a cyclic number.

It is not a de Polignac number, because 228805561 - 2¹³ = 228797369 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 228805561.

It is not an unprimeable number, because it can be changed into a prime (228808561) 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, 1285336 + ... + 1285513.

It is an arithmetic number, because the mean of its divisors is an integer number (57844125).

Almost surely, 2^228805561 is an apocalyptic number.

It is an amenable number.

228805561 is a deficient number, since it is larger than the sum of its proper divisors (2570939).

228805561 is an equidigital number, since it uses as much as digits as its factorization.

228805561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2570938.

The product of its (nonzero) digits is 38400, while the sum is 37.

The square root of 228805561 is about 15126.3201407348. The cubic root of 228805561 is about 611.6301118642.

It can be divided in two parts, 22880 and 5561, that added together give a triangular number (28441 = T₂₃₈).

The spelling of 228805561 in words is "two hundred twenty-eight million, eight hundred five thousand, five hundred sixty-one".