21982811 has 8 divisors (see below), whose sum is σ = 22302720. Its totient is φ = 21665448.

The previous prime is 21982801. The next prime is 21982817. The reversal of 21982811 is 11828912.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21982811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21982817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22250 + ... + 23216.

It is an arithmetic number, because the mean of its divisors is an integer number (2787840).

Almost surely, 2^21982811 is an apocalyptic number.

21982811 is a deficient number, since it is larger than the sum of its proper divisors (319909).

21982811 is a wasteful number, since it uses less digits than its factorization.

21982811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273.

The product of its digits is 2304, while the sum is 32.

The square root of 21982811 is about 4688.5830482140. The cubic root of 21982811 is about 280.1309379089.

The spelling of 21982811 in words is "twenty-one million, nine hundred eighty-two thousand, eight hundred eleven".