21266975 has 6 divisors (see below), whose sum is σ = 26371080. Its totient is φ = 17013560.

The previous prime is 21266953. The next prime is 21266977. The reversal of 21266975 is 57966212.

It is a happy number.

It is not a de Polignac number, because 21266975 - 2⁶ = 21266911 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 425315 + ... + 425364.

It is an arithmetic number, because the mean of its divisors is an integer number (4395180).

Almost surely, 2^21266975 is an apocalyptic number.

21266975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21266975 is a deficient number, since it is larger than the sum of its proper divisors (5104105).

21266975 is an equidigital number, since it uses as much as digits as its factorization.

21266975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850689 (or 850684 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 21266975 is about 4611.6130583560. The cubic root of 21266975 is about 277.0566466971.

The spelling of 21266975 in words is "twenty-one million, two hundred sixty-six thousand, nine hundred seventy-five".