21211039 has 2 divisors, whose sum is σ = 21211040. Its totient is φ = 21211038.

The previous prime is 21211033. The next prime is 21211079. The reversal of 21211039 is 93011212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21211039 - 2¹³ = 21202847 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605519 + 10605520.

It is an arithmetic number, because the mean of its divisors is an integer number (10605520).

Almost surely, 2^21211039 is an apocalyptic number.

21211039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211039 is an equidigital number, since it uses as much as digits as its factorization.

21211039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 21211039 is about 4605.5443760754. The cubic root of 21211039 is about 276.8135303551.

It can be divided in two parts, 2121 and 1039, that added together give a triangular number (3160 = T₇₉).

The spelling of 21211039 in words is "twenty-one million, two hundred eleven thousand, thirty-nine".