21383306 has 40 divisors (see below), whose sum is σ = 38552964. Its totient is φ = 8890560.

The previous prime is 21383291. The next prime is 21383309. The reversal of 21383306 is 60338312.

It can be written as a sum of positive squares in 2 ways, for example, as 19882681 + 1500625 = 4459^2 + 1225^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21383309) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 292886 + ... + 292958.

Almost surely, 2^21383306 is an apocalyptic number.

21383306 is a deficient number, since it is larger than the sum of its proper divisors (17169658).

21383306 is an frugal number, since it uses more digits than its factorization.

21383306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 21383306 is about 4624.2086890624. The cubic root of 21383306 is about 277.5608978164.

The spelling of 21383306 in words is "twenty-one million, three hundred eighty-three thousand, three hundred six".