225315021 has 16 divisors (see below), whose sum is σ = 305244288. Its totient is φ = 147806400.

The previous prime is 225315017. The next prime is 225315023. The reversal of 225315021 is 120513522.

225315021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 225315021 - 2² = 225315017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225315023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 211831 + ... + 212891.

It is an arithmetic number, because the mean of its divisors is an integer number (19077768).

Almost surely, 2^225315021 is an apocalyptic number.

It is an amenable number.

225315021 is a deficient number, since it is larger than the sum of its proper divisors (79929267).

225315021 is a wasteful number, since it uses less digits than its factorization.

225315021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2132.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 225315021 is about 15010.4970270807. The cubic root of 225315021 is about 608.5039222013.

Adding to 225315021 its reverse (120513522), we get a palindrome (345828543).

The spelling of 225315021 in words is "two hundred twenty-five million, three hundred fifteen thousand, twenty-one".