21814881 has 16 divisors (see below), whose sum is σ = 32253888. Its totient is φ = 13003200.

The previous prime is 21814843. The next prime is 21814901. The reversal of 21814881 is 18841812.

It is not a de Polignac number, because 21814881 - 2⁶ = 21814817 is a prime.

It is a super-2 number, since 2×21814881² = 951778066088322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21814811) 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 15 ways as a sum of consecutive naturals, for example, 3406 + ... + 7431.

It is an arithmetic number, because the mean of its divisors is an integer number (2015868).

Almost surely, 2^21814881 is an apocalyptic number.

It is an amenable number.

21814881 is a deficient number, since it is larger than the sum of its proper divisors (10439007).

21814881 is a wasteful number, since it uses less digits than its factorization.

21814881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10912.

The product of its digits is 4096, while the sum is 33.

The square root of 21814881 is about 4670.6403201274. The cubic root of 21814881 is about 279.4157929813.

The spelling of 21814881 in words is "twenty-one million, eight hundred fourteen thousand, eight hundred eighty-one".