21442163 has 2 divisors, whose sum is σ = 21442164. Its totient is φ = 21442162.

The previous prime is 21442159. The next prime is 21442229. The reversal of 21442163 is 36124412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21442163 - 2² = 21442159 is a prime.

It is not a weakly prime, because it can be changed into another prime (21442103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10721081 + 10721082.

It is an arithmetic number, because the mean of its divisors is an integer number (10721082).

Almost surely, 2^21442163 is an apocalyptic number.

21442163 is a deficient number, since it is larger than the sum of its proper divisors (1).

21442163 is an equidigital number, since it uses as much as digits as its factorization.

21442163 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 23.

The square root of 21442163 is about 4630.5683236510. The cubic root of 21442163 is about 277.8153242699.

Adding to 21442163 its reverse (36124412), we get a palindrome (57566575).

The spelling of 21442163 in words is "twenty-one million, four hundred forty-two thousand, one hundred sixty-three".