21271259 has 2 divisors, whose sum is σ = 21271260. Its totient is φ = 21271258.

The previous prime is 21271253. The next prime is 21271277. The reversal of 21271259 is 95217212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21271259 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21271253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10635629 + 10635630.

It is an arithmetic number, because the mean of its divisors is an integer number (10635630).

Almost surely, 2^21271259 is an apocalyptic number.

21271259 is a deficient number, since it is larger than the sum of its proper divisors (1).

21271259 is an equidigital number, since it uses as much as digits as its factorization.

21271259 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2520, while the sum is 29.

The square root of 21271259 is about 4612.0775145264. The cubic root of 21271259 is about 277.0752487940.

The spelling of 21271259 in words is "twenty-one million, two hundred seventy-one thousand, two hundred fifty-nine".