21862281 has 12 divisors (see below), whose sum is σ = 33909072. Its totient is φ = 12492648.

The previous prime is 21862241. The next prime is 21862297. The reversal of 21862281 is 18226812.

It is not a de Polignac number, because 21862281 - 2⁹ = 21861769 is a prime.

It is a super-2 number, since 2×21862281² = 955918661045922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21862241) 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 11 ways as a sum of consecutive naturals, for example, 74215 + ... + 74508.

It is an arithmetic number, because the mean of its divisors is an integer number (2825756).

Almost surely, 2^21862281 is an apocalyptic number.

21862281 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21862281 is a deficient number, since it is larger than the sum of its proper divisors (12046791).

21862281 is a wasteful number, since it uses less digits than its factorization.

21862281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148740 (or 148733 counting only the distinct ones).

The product of its digits is 3072, while the sum is 30.

The square root of 21862281 is about 4675.7118174669. The cubic root of 21862281 is about 279.6180208032.

The spelling of 21862281 in words is "twenty-one million, eight hundred sixty-two thousand, two hundred eighty-one".