21368733 has 8 divisors (see below), whose sum is σ = 28555296. Its totient is φ = 14214000.

The previous prime is 21368729. The next prime is 21368741. The reversal of 21368733 is 33786312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21368733 - 2² = 21368729 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21368694 and 21368703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21368713) 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 7 ways as a sum of consecutive naturals, for example, 6343 + ... + 9108.

It is an arithmetic number, because the mean of its divisors is an integer number (3569412).

Almost surely, 2^21368733 is an apocalyptic number.

It is an amenable number.

21368733 is a deficient number, since it is larger than the sum of its proper divisors (7186563).

21368733 is a wasteful number, since it uses less digits than its factorization.

21368733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15915.

The product of its digits is 18144, while the sum is 33.

The square root of 21368733 is about 4622.6326914433. The cubic root of 21368733 is about 277.4978297046.

The spelling of 21368733 in words is "twenty-one million, three hundred sixty-eight thousand, seven hundred thirty-three".