21983143 has 16 divisors (see below), whose sum is σ = 27791680. Its totient is φ = 16920576.

The previous prime is 21983111. The next prime is 21983149. The reversal of 21983143 is 34138912.

It is a 12-Lehmer number, since φ(21983143) divides (21983143-1)¹².

It is a cyclic number.

It is not a de Polignac number, because 21983143 - 2⁵ = 21983111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21983149) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103 + ... + 6631.

It is an arithmetic number, because the mean of its divisors is an integer number (1736980).

Almost surely, 2^21983143 is an apocalyptic number.

21983143 is a deficient number, since it is larger than the sum of its proper divisors (5808537).

21983143 is a wasteful number, since it uses less digits than its factorization.

21983143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6586.

The product of its digits is 5184, while the sum is 31.

The square root of 21983143 is about 4688.6184532333. The cubic root of 21983143 is about 280.1323481472.

The spelling of 21983143 in words is "twenty-one million, nine hundred eighty-three thousand, one hundred forty-three".