21366384 has 80 divisors (see below), whose sum is σ = 60225312. Its totient is φ = 6488064.

The previous prime is 21366377. The next prime is 21366391. The reversal of 21366384 is 48366312.

It is an interprime number because it is at equal distance from previous prime (21366377) and next prime (21366391).

It is a super-3 number, since 3×21366384³ (a number of 23 digits) contains 333 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60352 + ... + 60704.

Almost surely, 2^21366384 is an apocalyptic number.

21366384 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21366384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30112656).

21366384 is an abundant number, since it is smaller than the sum of its proper divisors (38858928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21366384 is a wasteful number, since it uses less digits than its factorization.

21366384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474 (or 468 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 21366384 is about 4622.3786084656. The cubic root of 21366384 is about 277.4876611671.

The spelling of 21366384 in words is "twenty-one million, three hundred sixty-six thousand, three hundred eighty-four".