21264653 has 4 divisors (see below), whose sum is σ = 21298368. Its totient is φ = 21230940.

The previous prime is 21264613. The next prime is 21264689. The reversal of 21264653 is 35646212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21264653 - 2²² = 17070349 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21264613) 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 in 3 ways as a sum of consecutive naturals, for example, 15893 + ... + 17178.

It is an arithmetic number, because the mean of its divisors is an integer number (5324592).

Almost surely, 2^21264653 is an apocalyptic number.

It is an amenable number.

21264653 is a deficient number, since it is larger than the sum of its proper divisors (33715).

21264653 is an equidigital number, since it uses as much as digits as its factorization.

21264653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33714.

The product of its digits is 8640, while the sum is 29.

The square root of 21264653 is about 4611.3612957564. The cubic root of 21264653 is about 277.0465630040.

The spelling of 21264653 in words is "twenty-one million, two hundred sixty-four thousand, six hundred fifty-three".