21983811 has 8 divisors (see below), whose sum is σ = 29571600. Its totient is φ = 14525952.

The previous prime is 21983807. The next prime is 21983861. The reversal of 21983811 is 11838912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21983811 - 2² = 21983807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21983861) 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, 32086 + ... + 32763.

It is an arithmetic number, because the mean of its divisors is an integer number (3696450).

Almost surely, 2^21983811 is an apocalyptic number.

21983811 is a deficient number, since it is larger than the sum of its proper divisors (7587789).

21983811 is a wasteful number, since it uses less digits than its factorization.

21983811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64965.

The product of its digits is 3456, while the sum is 33.

The square root of 21983811 is about 4688.6896890283. The cubic root of 21983811 is about 280.1351855715.

The spelling of 21983811 in words is "twenty-one million, nine hundred eighty-three thousand, eight hundred eleven".