21383489 has 4 divisors (see below), whose sum is σ = 21734100. Its totient is φ = 21032880.

The previous prime is 21383473. The next prime is 21383497. The reversal of 21383489 is 98438312.

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 297025 + 21086464 = 545^2 + 4592^2 .

It is a cyclic number.

It is not a de Polignac number, because 21383489 - 2⁴ = 21383473 is a prime.

It is a super-3 number, since 3×21383489³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21383419) 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, 175214 + ... + 175335.

It is an arithmetic number, because the mean of its divisors is an integer number (5433525).

Almost surely, 2^21383489 is an apocalyptic number.

It is an amenable number.

21383489 is a deficient number, since it is larger than the sum of its proper divisors (350611).

21383489 is an equidigital number, since it uses as much as digits as its factorization.

21383489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350610.

The product of its digits is 41472, while the sum is 38.

The square root of 21383489 is about 4624.2284761893. The cubic root of 21383489 is about 277.5616896100.

The spelling of 21383489 in words is "twenty-one million, three hundred eighty-three thousand, four hundred eighty-nine".