21764653 has 2 divisors, whose sum is σ = 21764654. Its totient is φ = 21764652.

The previous prime is 21764651. The next prime is 21764663. The reversal of 21764653 is 35646712.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21650409 + 114244 = 4653^2 + 338^2 .

It is a cyclic number.

It is not a de Polignac number, because 21764653 - 2¹ = 21764651 is a prime.

Together with 21764651, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21764651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10882326 + 10882327.

It is an arithmetic number, because the mean of its divisors is an integer number (10882327).

Almost surely, 2^21764653 is an apocalyptic number.

It is an amenable number.

21764653 is a deficient number, since it is larger than the sum of its proper divisors (1).

21764653 is an equidigital number, since it uses as much as digits as its factorization.

21764653 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 34.

The square root of 21764653 is about 4665.2602285403. The cubic root of 21764653 is about 279.2011798225.

The spelling of 21764653 in words is "twenty-one million, seven hundred sixty-four thousand, six hundred fifty-three".