21299143 has 2 divisors, whose sum is σ = 21299144. Its totient is φ = 21299142.

The previous prime is 21299141. The next prime is 21299149. The reversal of 21299143 is 34199212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21299143 - 2¹ = 21299141 is a prime.

Together with 21299141, 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 (21299141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10649571 + 10649572.

It is an arithmetic number, because the mean of its divisors is an integer number (10649572).

Almost surely, 2^21299143 is an apocalyptic number.

21299143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21299143 is an equidigital number, since it uses as much as digits as its factorization.

21299143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 31.

The square root of 21299143 is about 4615.0994572165. The cubic root of 21299143 is about 277.1962664351.

The spelling of 21299143 in words is "twenty-one million, two hundred ninety-nine thousand, one hundred forty-three".