21233375 has 16 divisors (see below), whose sum is σ = 27221376. Its totient is φ = 16524000.

The previous prime is 21233371. The next prime is 21233389. The reversal of 21233375 is 57333212.

It is not a de Polignac number, because 21233375 - 2² = 21233371 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2330 + ... + 6920.

It is an arithmetic number, because the mean of its divisors is an integer number (1701336).

Almost surely, 2^21233375 is an apocalyptic number.

21233375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21233375 is a deficient number, since it is larger than the sum of its proper divisors (5988001).

21233375 is an equidigital number, since it uses as much as digits as its factorization.

21233375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4643 (or 4633 counting only the distinct ones).

The product of its digits is 3780, while the sum is 26.

The square root of 21233375 is about 4607.9686413864. The cubic root of 21233375 is about 276.9106611935.

Adding to 21233375 its reverse (57333212), we get a palindrome (78566587).

The spelling of 21233375 in words is "twenty-one million, two hundred thirty-three thousand, three hundred seventy-five".