228431421 has 56 divisors (see below), whose sum is σ = 358853760. Its totient is φ = 145224576.

The previous prime is 228431407. The next prime is 228431429. The reversal of 228431421 is 124134822.

228431421 is a `hidden beast` number, since 228 + 431 + 4 + 2 + 1 = 666.

It is not a de Polignac number, because 228431421 - 2¹⁷ = 228300349 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228431429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 2021461 + ... + 2021573.

Almost surely, 2^228431421 is an apocalyptic number.

It is an amenable number.

228431421 is a deficient number, since it is larger than the sum of its proper divisors (130422339).

228431421 is an equidigital number, since it uses as much as digits as its factorization.

228431421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 237 (or 222 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 228431421 is about 15113.9478959007. The cubic root of 228431421 is about 611.2965533440.

It can be divided in two parts, 228 and 431421, that added together give a square (431649 = 657²).

The spelling of 228431421 in words is "two hundred twenty-eight million, four hundred thirty-one thousand, four hundred twenty-one".