21383653 has 4 divisors (see below), whose sum is σ = 21702880. Its totient is φ = 21064428.

The previous prime is 21383651. The next prime is 21383699. The reversal of 21383653 is 35638312.

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 21383653 - 2¹ = 21383651 is a prime.

It is a super-3 number, since 3×21383653³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21383651) 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, 159513 + ... + 159646.

It is an arithmetic number, because the mean of its divisors is an integer number (5425720).

Almost surely, 2^21383653 is an apocalyptic number.

It is an amenable number.

21383653 is a deficient number, since it is larger than the sum of its proper divisors (319227).

21383653 is an equidigital number, since it uses as much as digits as its factorization.

21383653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319226.

The product of its digits is 12960, while the sum is 31.

The square root of 21383653 is about 4624.2462088431. The cubic root of 21383653 is about 277.5623991918.

The spelling of 21383653 in words is "twenty-one million, three hundred eighty-three thousand, six hundred fifty-three".