21260969 has 4 divisors (see below), whose sum is σ = 21278544. Its totient is φ = 21243396.

The previous prime is 21260917. The next prime is 21260971. The reversal of 21260969 is 96906212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21260969 - 2²⁰ = 20212393 is a prime.

It is a super-2 number, since 2×21260969² = 904057605637922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21260989) 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, 6827 + ... + 9440.

It is an arithmetic number, because the mean of its divisors is an integer number (5319636).

Almost surely, 2^21260969 is an apocalyptic number.

It is an amenable number.

21260969 is a deficient number, since it is larger than the sum of its proper divisors (17575).

21260969 is a wasteful number, since it uses less digits than its factorization.

21260969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17574.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 21260969 is about 4610.9618302476. The cubic root of 21260969 is about 277.0305630802.

The spelling of 21260969 in words is "twenty-one million, two hundred sixty thousand, nine hundred sixty-nine".