21343187 has 2 divisors, whose sum is σ = 21343188. Its totient is φ = 21343186.

The previous prime is 21343163. The next prime is 21343243. The reversal of 21343187 is 78134312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21343187 - 2¹⁰ = 21342163 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21343787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10671593 + 10671594.

It is an arithmetic number, because the mean of its divisors is an integer number (10671594).

Almost surely, 2^21343187 is an apocalyptic number.

21343187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21343187 is an equidigital number, since it uses as much as digits as its factorization.

21343187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 29.

The square root of 21343187 is about 4619.8687210786. The cubic root of 21343187 is about 277.3872041105.

Adding to 21343187 its reverse (78134312), we get a palindrome (99477499).

The spelling of 21343187 in words is "twenty-one million, three hundred forty-three thousand, one hundred eighty-seven".