21067213 has 2 divisors, whose sum is σ = 21067214. Its totient is φ = 21067212.

The previous prime is 21067201. The next prime is 21067229. The reversal of 21067213 is 31276012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19474569 + 1592644 = 4413^2 + 1262^2 .

It is a cyclic number.

It is not a de Polignac number, because 21067213 - 2¹³ = 21059021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21067283) 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, 10533606 + 10533607.

It is an arithmetic number, because the mean of its divisors is an integer number (10533607).

Almost surely, 2^21067213 is an apocalyptic number.

It is an amenable number.

21067213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21067213 is an equidigital number, since it uses as much as digits as its factorization.

21067213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 21067213 is about 4589.9033758893. The cubic root of 21067213 is about 276.1864463452.

The spelling of 21067213 in words is "twenty-one million, sixty-seven thousand, two hundred thirteen".