21225653 has 2 divisors, whose sum is σ = 21225654. Its totient is φ = 21225652.

The previous prime is 21225649. The next prime is 21225661. The reversal of 21225653 is 35652212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18722929 + 2502724 = 4327^2 + 1582^2 .

It is a cyclic number.

It is not a de Polignac number, because 21225653 - 2² = 21225649 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21225613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612826 + 10612827.

It is an arithmetic number, because the mean of its divisors is an integer number (10612827).

Almost surely, 2^21225653 is an apocalyptic number.

It is an amenable number.

21225653 is a deficient number, since it is larger than the sum of its proper divisors (1).

21225653 is an equidigital number, since it uses as much as digits as its factorization.

21225653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 26.

The square root of 21225653 is about 4607.1306688654. The cubic root of 21225653 is about 276.8770888356.

Adding to 21225653 its reverse (35652212), we get a palindrome (56877865).

The spelling of 21225653 in words is "twenty-one million, two hundred twenty-five thousand, six hundred fifty-three".