21330653 has 4 divisors (see below), whose sum is σ = 21359808. Its totient is φ = 21301500.

The previous prime is 21330649. The next prime is 21330679. The reversal of 21330653 is 35603312.

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 21330653 - 2² = 21330649 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13451 + ... + 14952.

It is an arithmetic number, because the mean of its divisors is an integer number (5339952).

Almost surely, 2^21330653 is an apocalyptic number.

It is an amenable number.

21330653 is a deficient number, since it is larger than the sum of its proper divisors (29155).

21330653 is an equidigital number, since it uses as much as digits as its factorization.

21330653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29154.

The product of its (nonzero) digits is 1620, while the sum is 23.

The square root of 21330653 is about 4618.5119898080. The cubic root of 21330653 is about 277.3328940079.

Adding to 21330653 its reverse (35603312), we get a palindrome (56933965).

The spelling of 21330653 in words is "twenty-one million, three hundred thirty thousand, six hundred fifty-three".