21142291 has 2 divisors, whose sum is σ = 21142292. Its totient is φ = 21142290.

The previous prime is 21142273. The next prime is 21142343. The reversal of 21142291 is 19224112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21142291 - 2⁵ = 21142259 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21142201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571145 + 10571146.

It is an arithmetic number, because the mean of its divisors is an integer number (10571146).

Almost surely, 2^21142291 is an apocalyptic number.

21142291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142291 is an equidigital number, since it uses as much as digits as its factorization.

21142291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 22.

The square root of 21142291 is about 4598.0747057872. The cubic root of 21142291 is about 276.5141426362.

The spelling of 21142291 in words is "twenty-one million, one hundred forty-two thousand, two hundred ninety-one".