21289383 has 12 divisors (see below), whose sum is σ = 31273320. Its totient is φ = 13952016.

The previous prime is 21289381. The next prime is 21289399. The reversal of 21289383 is 38398212.

It is a happy number.

It is not a de Polignac number, because 21289383 - 2¹ = 21289381 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21289381) 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 11 ways as a sum of consecutive naturals, for example, 19516 + ... + 20577.

It is an arithmetic number, because the mean of its divisors is an integer number (2606110).

Almost surely, 2^21289383 is an apocalyptic number.

21289383 is a deficient number, since it is larger than the sum of its proper divisors (9983937).

21289383 is a wasteful number, since it uses less digits than its factorization.

21289383 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40158 (or 40155 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 21289383 is about 4614.0419373907. The cubic root of 21289383 is about 277.1539196780.

It can be divided in two parts, 2128 and 9383, that added together give a palindrome (11511).

The spelling of 21289383 in words is "twenty-one million, two hundred eighty-nine thousand, three hundred eighty-three".