21383689 has 4 divisors (see below), whose sum is σ = 21472660. Its totient is φ = 21294720.

The previous prime is 21383651. The next prime is 21383699. The reversal of 21383689 is 98638312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9363600 + 12020089 = 3060^2 + 3467^2 .

It is a cyclic number.

It is not a de Polignac number, because 21383689 - 2⁹ = 21383177 is a prime.

It is a super-3 number, since 3×21383689³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21383699) 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, 44124 + ... + 44605.

It is an arithmetic number, because the mean of its divisors is an integer number (5368165).

Almost surely, 2^21383689 is an apocalyptic number.

It is an amenable number.

21383689 is a deficient number, since it is larger than the sum of its proper divisors (88971).

21383689 is an equidigital number, since it uses as much as digits as its factorization.

21383689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88970.

The product of its digits is 62208, while the sum is 40.

The square root of 21383689 is about 4624.2501013678. The cubic root of 21383689 is about 277.5625549531.

The spelling of 21383689 in words is "twenty-one million, three hundred eighty-three thousand, six hundred eighty-nine".