21142213 has 2 divisors, whose sum is σ = 21142214. Its totient is φ = 21142212.

The previous prime is 21142201. The next prime is 21142223. The reversal of 21142213 is 31224112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12510369 + 8631844 = 3537^2 + 2938^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142213 - 2¹³ = 21134021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21142223) 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, 10571106 + 10571107.

It is an arithmetic number, because the mean of its divisors is an integer number (10571107).

Almost surely, 2^21142213 is an apocalyptic number.

It is an amenable number.

21142213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142213 is an equidigital number, since it uses as much as digits as its factorization.

21142213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 16.

The square root of 21142213 is about 4598.0662239685. The cubic root of 21142213 is about 276.5138025891.

Adding to 21142213 its reverse (31224112), we get a palindrome (52366325).

It can be divided in two parts, 211 and 42213, that added together give a palindrome (42424).

The spelling of 21142213 in words is "twenty-one million, one hundred forty-two thousand, two hundred thirteen".