228405731 has 4 divisors (see below), whose sum is σ = 230540472. Its totient is φ = 226270992.

The previous prime is 228405719. The next prime is 228405739. The reversal of 228405731 is 137504822.

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

It is a cyclic number.

It is not a de Polignac number, because 228405731 - 2¹⁴ = 228389347 is a prime.

It is a super-2 number, since 2×228405731² = 104338355907288722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (228405739) 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, 1067210 + ... + 1067423.

It is an arithmetic number, because the mean of its divisors is an integer number (57635118).

Almost surely, 2^228405731 is an apocalyptic number.

228405731 is a deficient number, since it is larger than the sum of its proper divisors (2134741).

228405731 is a wasteful number, since it uses less digits than its factorization.

228405731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2134740.

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 228405731 is about 15113.0979947858. The cubic root of 228405731 is about 611.2736364774.

Subtracting from 228405731 its reverse (137504822), we obtain a palindrome (90900909).

The spelling of 228405731 in words is "two hundred twenty-eight million, four hundred five thousand, seven hundred thirty-one".