21983243 has 4 divisors (see below), whose sum is σ = 21992880. Its totient is φ = 21973608.

The previous prime is 21983237. The next prime is 21983281. The reversal of 21983243 is 34238912.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21983243 - 2⁶ = 21983179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21980243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 746 + ... + 6672.

It is an arithmetic number, because the mean of its divisors is an integer number (5498220).

Almost surely, 2^21983243 is an apocalyptic number.

21983243 is a deficient number, since it is larger than the sum of its proper divisors (9637).

21983243 is an equidigital number, since it uses as much as digits as its factorization.

21983243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9636.

The product of its digits is 10368, while the sum is 32.

The square root of 21983243 is about 4688.6291173434. The cubic root of 21983243 is about 280.1327729149.

The spelling of 21983243 in words is "twenty-one million, nine hundred eighty-three thousand, two hundred forty-three".