21032375 has 48 divisors (see below), whose sum is σ = 33074496. Its totient is φ = 13003200.

The previous prime is 21032371. The next prime is 21032387. The reversal of 21032375 is 57323012.

It is not a de Polignac number, because 21032375 - 2² = 21032371 is a prime.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21032375.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21032371) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 489104 + ... + 489146.

It is an arithmetic number, because the mean of its divisors is an integer number (689052).

Almost surely, 2^21032375 is an apocalyptic number.

21032375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21032375 is a deficient number, since it is larger than the sum of its proper divisors (12042121).

21032375 is an equidigital number, since it uses as much as digits as its factorization.

21032375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 21032375 is about 4586.1067366558. The cubic root of 21032375 is about 276.0341228902.

Adding to 21032375 its reverse (57323012), we get a palindrome (78355387).

The spelling of 21032375 in words is "twenty-one million, thirty-two thousand, three hundred seventy-five".