21199265 has 4 divisors (see below), whose sum is σ = 25439124. Its totient is φ = 16959408.

The previous prime is 21199259. The next prime is 21199327. The reversal of 21199265 is 56299112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16394401 + 4804864 = 4049^2 + 2192^2 .

It is a cyclic number.

It is not a de Polignac number, because 21199265 - 2⁴ = 21199249 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2119922 + ... + 2119931.

It is an arithmetic number, because the mean of its divisors is an integer number (6359781).

Almost surely, 2^21199265 is an apocalyptic number.

It is an amenable number.

21199265 is a deficient number, since it is larger than the sum of its proper divisors (4239859).

21199265 is an equidigital number, since it uses as much as digits as its factorization.

21199265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4239858.

The product of its digits is 9720, while the sum is 35.

The square root of 21199265 is about 4604.2659566971. The cubic root of 21199265 is about 276.7623022227.

The spelling of 21199265 in words is "twenty-one million, one hundred ninety-nine thousand, two hundred sixty-five".