21226725 has 96 divisors (see below), whose sum is σ = 43747200. Its totient is φ = 10022400.

The previous prime is 21226703. The next prime is 21226729. The reversal of 21226725 is 52762212.

It is not a de Polignac number, because 21226725 - 2⁹ = 21226213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226729) 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 95 ways as a sum of consecutive naturals, for example, 359746 + ... + 359804.

It is an arithmetic number, because the mean of its divisors is an integer number (455700).

Almost surely, 2^21226725 is an apocalyptic number.

21226725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21226725 is an abundant number, since it is smaller than the sum of its proper divisors (22520475).

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

21226725 is a wasteful number, since it uses less digits than its factorization.

21226725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 121 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21226725 is about 4607.2470087895. The cubic root of 21226725 is about 276.8817499760.

Adding to 21226725 its reverse (52762212), we get a palindrome (73988937).

The spelling of 21226725 in words is "twenty-one million, two hundred twenty-six thousand, seven hundred twenty-five".