225721650 has 96 divisors (see below), whose sum is σ = 697955328. Its totient is φ = 46900800.

The previous prime is 225721637. The next prime is 225721651. The reversal of 225721650 is 56127522.

225721650 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (225721651) 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, 1779 + ... + 21321.

It is an arithmetic number, because the mean of its divisors is an integer number (7270368).

Almost surely, 2^225721650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 225721650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (348977664).

225721650 is an abundant number, since it is smaller than the sum of its proper divisors (472233678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

225721650 is a wasteful number, since it uses less digits than its factorization.

225721650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19576 (or 19571 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 225721650 is about 15024.0357427690. The cubic root of 225721650 is about 608.8697605720.

The spelling of 225721650 in words is "two hundred twenty-five million, seven hundred twenty-one thousand, six hundred fifty".