21983808 has 112 divisors (see below), whose sum is σ = 72566784. Its totient is φ = 5706240.

The previous prime is 21983807. The next prime is 21983861. The reversal of 21983808 is 80838912.

It is a tau number, because it is divible by the number of its divisors (112).

It is not an unprimeable number, because it can be changed into a prime (21983807) 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, 14041 + ... + 15527.

Almost surely, 2^21983808 is an apocalyptic number.

21983808 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 21983808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36283392).

21983808 is an abundant number, since it is smaller than the sum of its proper divisors (50582976).

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

21983808 is a wasteful number, since it uses less digits than its factorization.

21983808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1520 (or 1510 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 21983808 is about 4688.6893691095. The cubic root of 21983808 is about 280.1351728287.

It can be divided in two parts, 21983 and 808, that added together give a triangular number (22791 = T₂₁₃).

The spelling of 21983808 in words is "twenty-one million, nine hundred eighty-three thousand, eight hundred eight".