21883818 has 48 divisors (see below), whose sum is σ = 49297248. Its totient is φ = 6468000.

The previous prime is 21883817. The next prime is 21883819. The reversal of 21883818 is 81838812.

It is an interprime number because it is at equal distance from previous prime (21883817) and next prime (21883819).

It is not an unprimeable number, because it can be changed into a prime (21883817) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30868 + ... + 31568.

It is an arithmetic number, because the mean of its divisors is an integer number (1027026).

Almost surely, 2^21883818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21883818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24648624).

21883818 is an abundant number, since it is smaller than the sum of its proper divisors (27413430).

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

21883818 is a wasteful number, since it uses less digits than its factorization.

21883818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 771 (or 760 counting only the distinct ones).

The product of its digits is 24576, while the sum is 39.

The square root of 21883818 is about 4678.0143223381. The cubic root of 21883818 is about 279.7098098971.

It can be divided in two parts, 2188 and 3818, that added together give a palindrome (6006).

The spelling of 21883818 in words is "twenty-one million, eight hundred eighty-three thousand, eight hundred eighteen".