21356143 has 2 divisors, whose sum is σ = 21356144. Its totient is φ = 21356142.

The previous prime is 21356129. The next prime is 21356177. The reversal of 21356143 is 34165312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21356143 - 2¹³ = 21347951 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21350143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678071 + 10678072.

It is an arithmetic number, because the mean of its divisors is an integer number (10678072).

Almost surely, 2^21356143 is an apocalyptic number.

21356143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21356143 is an equidigital number, since it uses as much as digits as its factorization.

21356143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 25.

The square root of 21356143 is about 4621.2707126936. The cubic root of 21356143 is about 277.4433204046.

The spelling of 21356143 in words is "twenty-one million, three hundred fifty-six thousand, one hundred forty-three".