21818983 has 2 divisors, whose sum is σ = 21818984. Its totient is φ = 21818982.

The previous prime is 21818963. The next prime is 21819001. The reversal of 21818983 is 38981812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21818983 - 2⁹ = 21818471 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21818963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10909491 + 10909492.

It is an arithmetic number, because the mean of its divisors is an integer number (10909492).

Almost surely, 2^21818983 is an apocalyptic number.

21818983 is a deficient number, since it is larger than the sum of its proper divisors (1).

21818983 is an equidigital number, since it uses as much as digits as its factorization.

21818983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 40.

The square root of 21818983 is about 4671.0794255718. The cubic root of 21818983 is about 279.4333053658.

It can be divided in two parts, 21818 and 983, that added together give a square (22801 = 151²).

The spelling of 21818983 in words is "twenty-one million, eight hundred eighteen thousand, nine hundred eighty-three".