228420405 has 30 divisors (see below), whose sum is σ = 410010678. Its totient is φ = 121662000.

The previous prime is 228420403. The next prime is 228420421. The reversal of 228420405 is 504024822.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 182736324 + 45684081 = 13518^2 + 6759^2 .

It is not a de Polignac number, because 228420405 - 2¹ = 228420403 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (228420403) 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 29 ways as a sum of consecutive naturals, for example, 303780 + ... + 304530.

Almost surely, 2^228420405 is an apocalyptic number.

It is an amenable number.

228420405 is a deficient number, since it is larger than the sum of its proper divisors (181590273).

228420405 is an frugal number, since it uses more digits than its factorization.

228420405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1519 (or 759 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 27.

The square root of 228420405 is about 15113.5834599211. The cubic root of 228420405 is about 611.2867266878.

Multiplying 228420405 by its product of nonzero digits (5120), we get a square (1169512473600 = 1081440²).

The spelling of 228420405 in words is "two hundred twenty-eight million, four hundred twenty thousand, four hundred five".