225756421 has 12 divisors (see below), whose sum is σ = 249174144. Its totient is φ = 202848800.

The previous prime is 225756403. The next prime is 225756437. The reversal of 225756421 is 124657522.

It is not a de Polignac number, because 225756421 - 2¹⁷ = 225625349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225756451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85836 + ... + 88426.

It is an arithmetic number, because the mean of its divisors is an integer number (20764512).

Almost surely, 2^225756421 is an apocalyptic number.

It is an amenable number.

225756421 is a deficient number, since it is larger than the sum of its proper divisors (23417723).

225756421 is an equidigital number, since it uses as much as digits as its factorization.

225756421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2780 (or 2691 counting only the distinct ones).

The product of its digits is 33600, while the sum is 34.

The square root of 225756421 is about 15025.1928772978. The cubic root of 225756421 is about 608.9010231520.

The spelling of 225756421 in words is "two hundred twenty-five million, seven hundred fifty-six thousand, four hundred twenty-one".