21000267 has 12 divisors (see below), whose sum is σ = 30613440. Its totient is φ = 13871088.

The previous prime is 21000251. The next prime is 21000269. The reversal of 21000267 is 76200012.

It is a happy number.

It is not a de Polignac number, because 21000267 - 2⁴ = 21000251 is a prime.

It is a super-2 number, since 2×21000267² = 882022428142578, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21000269) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9723 + ... + 11684.

It is an arithmetic number, because the mean of its divisors is an integer number (2551120).

Almost surely, 2^21000267 is an apocalyptic number.

21000267 is a deficient number, since it is larger than the sum of its proper divisors (9613173).

21000267 is a wasteful number, since it uses less digits than its factorization.

21000267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21522 (or 21519 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21000267 is about 4582.6048269516. The cubic root of 21000267 is about 275.8935868915.

Adding to 21000267 its reverse (76200012), we get a palindrome (97200279).

The spelling of 21000267 in words is "twenty-one million, two hundred sixty-seven", and thus it is an aban number.