21465818 has 16 divisors (see below), whose sum is σ = 35470656. Its totient is φ = 9661440.

The previous prime is 21465817. The next prime is 21465823. The reversal of 21465818 is 81856412.

It is not an unprimeable number, because it can be changed into a prime (21465817) 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, 2471 + ... + 7002.

It is an arithmetic number, because the mean of its divisors is an integer number (2216916).

Almost surely, 2^21465818 is an apocalyptic number.

21465818 is a deficient number, since it is larger than the sum of its proper divisors (14004838).

21465818 is a wasteful number, since it uses less digits than its factorization.

21465818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9589.

The product of its digits is 15360, while the sum is 35.

The square root of 21465818 is about 4633.1218416959. The cubic root of 21465818 is about 277.9174487047.

The spelling of 21465818 in words is "twenty-one million, four hundred sixty-five thousand, eight hundred eighteen".