21142141 has 2 divisors, whose sum is σ = 21142142. Its totient is φ = 21142140.

The previous prime is 21142139. The next prime is 21142153. The reversal of 21142141 is 14124112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20738916 + 403225 = 4554^2 + 635^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142141 - 2¹ = 21142139 is a prime.

Together with 21142139, 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 (21142171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571070 + 10571071.

It is an arithmetic number, because the mean of its divisors is an integer number (10571071).

Almost surely, 2^21142141 is an apocalyptic number.

It is an amenable number.

21142141 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142141 is an equidigital number, since it uses as much as digits as its factorization.

21142141 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64, while the sum is 16.

The square root of 21142141 is about 4598.0583945835. The cubic root of 21142141 is about 276.5134886986.

Adding to 21142141 its reverse (14124112), we get a palindrome (35266253).

The spelling of 21142141 in words is "twenty-one million, one hundred forty-two thousand, one hundred forty-one".