21202143 has 4 divisors (see below), whose sum is σ = 28269528. Its totient is φ = 14134760.

The previous prime is 21202141. The next prime is 21202177. The reversal of 21202143 is 34120212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21202143 - 2¹ = 21202141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202141) 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 3 ways as a sum of consecutive naturals, for example, 3533688 + ... + 3533693.

It is an arithmetic number, because the mean of its divisors is an integer number (7067382).

Almost surely, 2^21202143 is an apocalyptic number.

21202143 is a deficient number, since it is larger than the sum of its proper divisors (7067385).

21202143 is an equidigital number, since it uses as much as digits as its factorization.

21202143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7067384.

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

The square root of 21202143 is about 4604.5784823369. The cubic root of 21202143 is about 276.7748260195.

Adding to 21202143 its reverse (34120212), we get a palindrome (55322355).

The spelling of 21202143 in words is "twenty-one million, two hundred two thousand, one hundred forty-three".