21383643 has 8 divisors (see below), whose sum is σ = 29494800. Its totient is φ = 13764128.

The previous prime is 21383633. The next prime is 21383651. The reversal of 21383643 is 34638312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21383643 - 2¹⁷ = 21252571 is a prime.

It is a super-3 number, since 3×21383643³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21383643.

It is not an unprimeable number, because it can be changed into a prime (21383633) 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 in 7 ways as a sum of consecutive naturals, for example, 122808 + ... + 122981.

It is an arithmetic number, because the mean of its divisors is an integer number (3686850).

Almost surely, 2^21383643 is an apocalyptic number.

21383643 is a deficient number, since it is larger than the sum of its proper divisors (8111157).

21383643 is a wasteful number, since it uses less digits than its factorization.

21383643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245821.

The product of its digits is 10368, while the sum is 30.

The square root of 21383643 is about 4624.2451275857. The cubic root of 21383643 is about 277.5623559247.

The spelling of 21383643 in words is "twenty-one million, three hundred eighty-three thousand, six hundred forty-three".