21335143 has 2 divisors, whose sum is σ = 21335144. Its totient is φ = 21335142.

The previous prime is 21335141. The next prime is 21335173. The reversal of 21335143 is 34153312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21335143 - 2¹ = 21335141 is a prime.

Together with 21335141, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21335141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667571 + 10667572.

It is an arithmetic number, because the mean of its divisors is an integer number (10667572).

Almost surely, 2^21335143 is an apocalyptic number.

21335143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21335143 is an equidigital number, since it uses as much as digits as its factorization.

21335143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1080, while the sum is 22.

The square root of 21335143 is about 4618.9980515259. The cubic root of 21335143 is about 277.3523517234.

Adding to 21335143 its reverse (34153312), we get a palindrome (55488455).

The spelling of 21335143 in words is "twenty-one million, three hundred thirty-five thousand, one hundred forty-three".