21920733 has 8 divisors (see below), whose sum is σ = 32475200. Its totient is φ = 14613804.

The previous prime is 21920711. The next prime is 21920741. The reversal of 21920733 is 33702912.

It is not a de Polignac number, because 21920733 - 2¹⁷ = 21789661 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 811879 = 21920733 / (2 + 1 + 9 + 2 + 0 + 7 + 3 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21920697 and 21920706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21921733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405913 + ... + 405966.

It is an arithmetic number, because the mean of its divisors is an integer number (4059400).

Almost surely, 2^21920733 is an apocalyptic number.

It is an amenable number.

21920733 is a deficient number, since it is larger than the sum of its proper divisors (10554467).

21920733 is an equidigital number, since it uses as much as digits as its factorization.

21920733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 811888 (or 811882 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 21920733 is about 4681.9582441538. The cubic root of 21920733 is about 279.8669989088.

The spelling of 21920733 in words is "twenty-one million, nine hundred twenty thousand, seven hundred thirty-three".