21267869 has 4 divisors (see below), whose sum is σ = 24306144. Its totient is φ = 18229596.

The previous prime is 21267863. The next prime is 21267871. The reversal of 21267869 is 96876212.

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 not a de Polignac number, because 21267869 - 2⁴ = 21267853 is a prime.

It is a super-2 number, since 2×21267869² = 904644503602322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21267863) 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, 1519127 + ... + 1519140.

It is an arithmetic number, because the mean of its divisors is an integer number (6076536).

Almost surely, 2^21267869 is an apocalyptic number.

It is an amenable number.

21267869 is a deficient number, since it is larger than the sum of its proper divisors (3038275).

21267869 is an equidigital number, since it uses as much as digits as its factorization.

21267869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3038274.

The product of its digits is 72576, while the sum is 41.

The square root of 21267869 is about 4611.7099865451. The cubic root of 21267869 is about 277.0605288535.

The spelling of 21267869 in words is "twenty-one million, two hundred sixty-seven thousand, eight hundred sixty-nine".