21845375 has 8 divisors (see below), whose sum is σ = 27263184. Its totient is φ = 17476200.

The previous prime is 21845353. The next prime is 21845387. The reversal of 21845375 is 57354812.

It is a happy number.

It is not a de Polignac number, because 21845375 - 2⁶ = 21845311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87257 + ... + 87506.

It is an arithmetic number, because the mean of its divisors is an integer number (3407898).

Almost surely, 2^21845375 is an apocalyptic number.

21845375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21845375 is a deficient number, since it is larger than the sum of its proper divisors (5417809).

21845375 is an equidigital number, since it uses as much as digits as its factorization.

21845375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174778 (or 174768 counting only the distinct ones).

The product of its digits is 33600, while the sum is 35.

The square root of 21845375 is about 4673.9036147529. The cubic root of 21845375 is about 279.5459264459.

The spelling of 21845375 in words is "twenty-one million, eight hundred forty-five thousand, three hundred seventy-five".