21245267 has 4 divisors (see below), whose sum is σ = 21259176. Its totient is φ = 21231360.

The previous prime is 21245227. The next prime is 21245281. The reversal of 21245267 is 76254212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21245267 - 2¹⁰ = 21244243 is a prime.

It is a super-2 number, since 2×21245267² = 902722739802578, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21245227) 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 in 3 ways as a sum of consecutive naturals, for example, 4334 + ... + 7827.

It is an arithmetic number, because the mean of its divisors is an integer number (5314794).

Almost surely, 2^21245267 is an apocalyptic number.

21245267 is a deficient number, since it is larger than the sum of its proper divisors (13909).

21245267 is a wasteful number, since it uses less digits than its factorization.

21245267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13908.

The product of its digits is 6720, while the sum is 29.

The square root of 21245267 is about 4609.2588341294. The cubic root of 21245267 is about 276.9623472304.

Adding to 21245267 its reverse (76254212), we get a palindrome (97499479).

It can be divided in two parts, 21245 and 267, that added together give a palindrome (21512).

The spelling of 21245267 in words is "twenty-one million, two hundred forty-five thousand, two hundred sixty-seven".