21109733 has 8 divisors (see below), whose sum is σ = 22524480. Its totient is φ = 19714240.

The previous prime is 21109727. The next prime is 21109763. The reversal of 21109733 is 33790112.

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

It is a cyclic number.

It is not a de Polignac number, because 21109733 - 2¹⁶ = 21044197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21109763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2513 + ... + 6966.

It is an arithmetic number, because the mean of its divisors is an integer number (2815560).

Almost surely, 2^21109733 is an apocalyptic number.

It is an amenable number.

21109733 is a deficient number, since it is larger than the sum of its proper divisors (1414747).

21109733 is a wasteful number, since it uses less digits than its factorization.

21109733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9627.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 21109733 is about 4594.5329468837. The cubic root of 21109733 is about 276.3721307060.

Adding to 21109733 its reverse (33790112), we get a palindrome (54899845).

The spelling of 21109733 in words is "twenty-one million, one hundred nine thousand, seven hundred thirty-three".