21816735 has 16 divisors (see below), whose sum is σ = 35124864. Its totient is φ = 11562912.

The previous prime is 21816733. The next prime is 21816749. The reversal of 21816735 is 53761812.

It is not a de Polignac number, because 21816735 - 2¹ = 21816733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21816696 and 21816705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21816733) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2017 + ... + 6906.

It is an arithmetic number, because the mean of its divisors is an integer number (2195304).

Almost surely, 2^21816735 is an apocalyptic number.

21816735 is a deficient number, since it is larger than the sum of its proper divisors (13308129).

21816735 is a wasteful number, since it uses less digits than its factorization.

21816735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9094.

The product of its digits is 10080, while the sum is 33.

The square root of 21816735 is about 4670.8387897679. The cubic root of 21816735 is about 279.4237084069.

The spelling of 21816735 in words is "twenty-one million, eight hundred sixteen thousand, seven hundred thirty-five".