21129267 has 8 divisors (see below), whose sum is σ = 28210896. Its totient is φ = 14066912.

The previous prime is 21129263. The next prime is 21129287. The reversal of 21129267 is 76292112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21129267 - 2² = 21129263 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21129263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2028 + ... + 6809.

It is an arithmetic number, because the mean of its divisors is an integer number (3526362).

Almost surely, 2^21129267 is an apocalyptic number.

21129267 is a deficient number, since it is larger than the sum of its proper divisors (7081629).

21129267 is an equidigital number, since it uses as much as digits as its factorization.

21129267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9637.

The product of its digits is 3024, while the sum is 30.

The square root of 21129267 is about 4596.6582426802. The cubic root of 21129267 is about 276.4573518823.

The spelling of 21129267 in words is "twenty-one million, one hundred twenty-nine thousand, two hundred sixty-seven".