21327653 has 2 divisors, whose sum is σ = 21327654. Its totient is φ = 21327652.

The previous prime is 21327637. The next prime is 21327689. The reversal of 21327653 is 35672312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20994724 + 332929 = 4582^2 + 577^2 .

It is a cyclic number.

It is not a de Polignac number, because 21327653 - 2⁴ = 21327637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21327353) 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 as a sum of consecutive naturals, namely, 10663826 + 10663827.

It is an arithmetic number, because the mean of its divisors is an integer number (10663827).

Almost surely, 2^21327653 is an apocalyptic number.

It is an amenable number.

21327653 is a deficient number, since it is larger than the sum of its proper divisors (1).

21327653 is an equidigital number, since it uses as much as digits as its factorization.

21327653 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 29.

The square root of 21327653 is about 4618.1871984579. The cubic root of 21327653 is about 277.3198917854.

Adding to 21327653 its reverse (35672312), we get a palindrome (56999965).

The spelling of 21327653 in words is "twenty-one million, three hundred twenty-seven thousand, six hundred fifty-three".