21267975 has 12 divisors (see below), whose sum is σ = 35163176. Its totient is φ = 11342880.

The previous prime is 21267941. The next prime is 21267989. The reversal of 21267975 is 57976212.

It is not a de Polignac number, because 21267975 - 2¹⁰ = 21266951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141712 + ... + 141861.

Almost surely, 2^21267975 is an apocalyptic number.

21267975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21267975 is a deficient number, since it is larger than the sum of its proper divisors (13895201).

21267975 is a wasteful number, since it uses less digits than its factorization.

21267975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283586 (or 283581 counting only the distinct ones).

The product of its digits is 52920, while the sum is 39.

The square root of 21267975 is about 4611.7214790141. The cubic root of 21267975 is about 277.0609891467.

It can be divided in two parts, 2126 and 7975, that added together give a palindrome (10101).

The spelling of 21267975 in words is "twenty-one million, two hundred sixty-seven thousand, nine hundred seventy-five".