21703818 has 32 divisors (see below), whose sum is σ = 44649792. Its totient is φ = 7030400.

The previous prime is 21703817. The next prime is 21703823. The reversal of 21703818 is 81830712.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21703817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41398 + ... + 41918.

It is an arithmetic number, because the mean of its divisors is an integer number (1395306).

Almost surely, 2^21703818 is an apocalyptic number.

21703818 is an abundant number, since it is smaller than the sum of its proper divisors (22945974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21703818 is a wasteful number, since it uses less digits than its factorization.

21703818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 21703818 is about 4658.7356653925. The cubic root of 21703818 is about 278.9408026922.

The spelling of 21703818 in words is "twenty-one million, seven hundred three thousand, eight hundred eighteen".