181428225 has 48 divisors (see below), whose sum is σ = 334264320. Its totient is φ = 86075200.

The previous prime is 181428197. The next prime is 181428229. The reversal of 181428225 is 522824181.

It is not a de Polignac number, because 181428225 - 2⁵ = 181428193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (181428229) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 36436 + ... + 41114.

It is an arithmetic number, because the mean of its divisors is an integer number (6963840).

Almost surely, 2^181428225 is an apocalyptic number.

181428225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

181428225 is a deficient number, since it is larger than the sum of its proper divisors (152836095).

181428225 is a wasteful number, since it uses less digits than its factorization.

181428225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4750 (or 4745 counting only the distinct ones).

The product of its digits is 10240, while the sum is 33.

The square root of 181428225 is about 13469.5295018052. The cubic root of 181428225 is about 566.1110307137. Note that the first 3 decimals are identical.

The spelling of 181428225 in words is "one hundred eighty-one million, four hundred twenty-eight thousand, two hundred twenty-five".