21943208 has 32 divisors (see below), whose sum is σ = 47597760. Its totient is φ = 9288960.

The previous prime is 21943199. The next prime is 21943211. The reversal of 21943208 is 80234912.

It is an unprimeable number.

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, 2288 + ... + 7008.

It is an arithmetic number, because the mean of its divisors is an integer number (1487430).

Almost surely, 2^21943208 is an apocalyptic number.

21943208 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21943208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23798880).

21943208 is an abundant number, since it is smaller than the sum of its proper divisors (25654552).

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

21943208 is a wasteful number, since it uses less digits than its factorization.

21943208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4817 (or 4813 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21943208 is about 4684.3578001686. The cubic root of 21943208 is about 279.9626140560.

The spelling of 21943208 in words is "twenty-one million, nine hundred forty-three thousand, two hundred eight".