21388675 has 48 divisors (see below), whose sum is σ = 33997824. Its totient is φ = 12960000.

The previous prime is 21388663. The next prime is 21388681. The reversal of 21388675 is 57688312.

It is not a de Polignac number, because 21388675 - 2¹⁹ = 20864387 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 78790 + ... + 79060.

It is an arithmetic number, because the mean of its divisors is an integer number (708288).

Almost surely, 2^21388675 is an apocalyptic number.

21388675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21388675 is a deficient number, since it is larger than the sum of its proper divisors (12609149).

21388675 is a wasteful number, since it uses less digits than its factorization.

21388675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340 (or 335 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 21388675 is about 4624.7891843845. The cubic root of 21388675 is about 277.5841262132.

It can be divided in two parts, 213 and 88675, that added together give a palindrome (88888).

The spelling of 21388675 in words is "twenty-one million, three hundred eighty-eight thousand, six hundred seventy-five".