225206421 has 16 divisors (see below), whose sum is σ = 327924288. Its totient is φ = 136342400.

The previous prime is 225206417. The next prime is 225206447. The reversal of 225206421 is 124602522.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 225206421 - 2² = 225206417 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 225206391 and 225206400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225206461) 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 15 ways as a sum of consecutive naturals, for example, 33091 + ... + 39311.

It is an arithmetic number, because the mean of its divisors is an integer number (20495268).

Almost surely, 2^225206421 is an apocalyptic number.

It is an amenable number.

225206421 is a deficient number, since it is larger than the sum of its proper divisors (102717867).

225206421 is a wasteful number, since it uses less digits than its factorization.

225206421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7332.

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 225206421 is about 15006.8791225891. The cubic root of 225206421 is about 608.4061418495.

Adding to 225206421 its reverse (124602522), we get a palindrome (349808943).

The spelling of 225206421 in words is "two hundred twenty-five million, two hundred six thousand, four hundred twenty-one".