21220143 has 16 divisors (see below), whose sum is σ = 32422656. Its totient is φ = 12093120.

The previous prime is 21220109. The next prime is 21220153. The reversal of 21220143 is 34102212.

It is not a de Polignac number, because 21220143 - 2⁹ = 21219631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8163 + ... + 10443.

It is an arithmetic number, because the mean of its divisors is an integer number (2026416).

Almost surely, 2^21220143 is an apocalyptic number.

21220143 is a deficient number, since it is larger than the sum of its proper divisors (11202513).

21220143 is a wasteful number, since it uses less digits than its factorization.

21220143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2734.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21220143 is about 4606.5326439742. The cubic root of 21220143 is about 276.8531284454.

Adding to 21220143 its reverse (34102212), we get a palindrome (55322355).

The spelling of 21220143 in words is "twenty-one million, two hundred twenty thousand, one hundred forty-three".