21049271 has 2 divisors, whose sum is σ = 21049272. Its totient is φ = 21049270.

The previous prime is 21049243. The next prime is 21049289. The reversal of 21049271 is 17294012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21049271 - 2¹⁸ = 20787127 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21049271.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21049201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10524635 + 10524636.

It is an arithmetic number, because the mean of its divisors is an integer number (10524636).

Almost surely, 2^21049271 is an apocalyptic number.

21049271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21049271 is an equidigital number, since it uses as much as digits as its factorization.

21049271 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 21049271 is about 4587.9484521952. The cubic root of 21049271 is about 276.1080188755.

The spelling of 21049271 in words is "twenty-one million, forty-nine thousand, two hundred seventy-one".