21045143 has 12 divisors (see below), whose sum is σ = 24592272. Its totient is φ = 17641920.

The previous prime is 21045139. The next prime is 21045149. The reversal of 21045143 is 34154012.

It is not a de Polignac number, because 21045143 - 2² = 21045139 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21045149) 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 11 ways as a sum of consecutive naturals, for example, 14783 + ... + 16143.

It is an arithmetic number, because the mean of its divisors is an integer number (2049356).

Almost surely, 2^21045143 is an apocalyptic number.

21045143 is a deficient number, since it is larger than the sum of its proper divisors (3547129).

21045143 is an equidigital number, since it uses as much as digits as its factorization.

21045143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1462 (or 1415 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21045143 is about 4587.4985558581. The cubic root of 21045143 is about 276.0899683942.

Adding to 21045143 its reverse (34154012), we get a palindrome (55199155).

The spelling of 21045143 in words is "twenty-one million, forty-five thousand, one hundred forty-three".