21253675 has 6 divisors (see below), whose sum is σ = 26354588. Its totient is φ = 17002920.

The previous prime is 21253667. The next prime is 21253697. The reversal of 21253675 is 57635212.

It is not a de Polignac number, because 21253675 - 2³ = 21253667 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 425049 + ... + 425098.

Almost surely, 2^21253675 is an apocalyptic number.

21253675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21253675 is a deficient number, since it is larger than the sum of its proper divisors (5100913).

21253675 is an equidigital number, since it uses as much as digits as its factorization.

21253675 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850157 (or 850152 counting only the distinct ones).

The product of its digits is 12600, while the sum is 31.

The square root of 21253675 is about 4610.1708211302. The cubic root of 21253675 is about 276.9988791676.

Adding to 21253675 its reverse (57635212), we get a palindrome (78888887).

The spelling of 21253675 in words is "twenty-one million, two hundred fifty-three thousand, six hundred seventy-five".