21265259 has 2 divisors, whose sum is σ = 21265260. Its totient is φ = 21265258.

The previous prime is 21265253. The next prime is 21265273. The reversal of 21265259 is 95256212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21265259 - 2¹⁶ = 21199723 is a prime.

It is a super-2 number, since 2×21265259² = 904422480674162, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21265253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10632629 + 10632630.

It is an arithmetic number, because the mean of its divisors is an integer number (10632630).

Almost surely, 2^21265259 is an apocalyptic number.

21265259 is a deficient number, since it is larger than the sum of its proper divisors (1).

21265259 is an equidigital number, since it uses as much as digits as its factorization.

21265259 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 32.

The square root of 21265259 is about 4611.4270025666. The cubic root of 21265259 is about 277.0491947363.

The spelling of 21265259 in words is "twenty-one million, two hundred sixty-five thousand, two hundred fifty-nine".