21225373 has 8 divisors (see below), whose sum is σ = 22950648. Its totient is φ = 19513344.

The previous prime is 21225353. The next prime is 21225397. The reversal of 21225373 is 37352212.

It can be written as a sum of positive squares in 4 ways, for example, as 5008644 + 16216729 = 2238^2 + 4027^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21225373 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 (21225353) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165 + ... + 6517.

It is an arithmetic number, because the mean of its divisors is an integer number (2868831).

Almost surely, 2^21225373 is an apocalyptic number.

It is an amenable number.

21225373 is a deficient number, since it is larger than the sum of its proper divisors (1725275).

21225373 is a wasteful number, since it uses less digits than its factorization.

21225373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6623.

The product of its digits is 2520, while the sum is 25.

The square root of 21225373 is about 4607.1002810879. The cubic root of 21225373 is about 276.8758713478.

Adding to 21225373 its reverse (37352212), we get a palindrome (58577585).

The spelling of 21225373 in words is "twenty-one million, two hundred twenty-five thousand, three hundred seventy-three".