21267371 has 2 divisors, whose sum is σ = 21267372. Its totient is φ = 21267370.

The previous prime is 21267263. The next prime is 21267383. The reversal of 21267371 is 17376212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21267371 - 2¹⁸ = 21005227 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21267871) 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, 10633685 + 10633686.

It is an arithmetic number, because the mean of its divisors is an integer number (10633686).

Almost surely, 2^21267371 is an apocalyptic number.

21267371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21267371 is an equidigital number, since it uses as much as digits as its factorization.

21267371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 29.

The square root of 21267371 is about 4611.6559932415. The cubic root of 21267371 is about 277.0583663234.

The spelling of 21267371 in words is "twenty-one million, two hundred sixty-seven thousand, three hundred seventy-one".