225156021 has 4 divisors (see below), whose sum is σ = 300208032. Its totient is φ = 150104012.

The previous prime is 225155999. The next prime is 225156047. The reversal of 225156021 is 120651522.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 225156021 - 2⁹ = 225155509 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 225155982 and 225156000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225156091) 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, 37526001 + ... + 37526006.

It is an arithmetic number, because the mean of its divisors is an integer number (75052008).

Almost surely, 2^225156021 is an apocalyptic number.

It is an amenable number.

225156021 is a deficient number, since it is larger than the sum of its proper divisors (75052011).

225156021 is an equidigital number, since it uses as much as digits as its factorization.

225156021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75052010.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 225156021 is about 15005.1997987364. The cubic root of 225156021 is about 608.3607524432.

The spelling of 225156021 in words is "two hundred twenty-five million, one hundred fifty-six thousand, twenty-one".