21027375 has 24 divisors (see below), whose sum is σ = 37907376. Its totient is φ = 11214000.

The previous prime is 21027373. The next prime is 21027389. The reversal of 21027375 is 57372012.

It is not a de Polignac number, because 21027375 - 2¹ = 21027373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21027373) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8221 + ... + 10470.

It is an arithmetic number, because the mean of its divisors is an integer number (1579474).

Almost surely, 2^21027375 is an apocalyptic number.

21027375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21027375 is a deficient number, since it is larger than the sum of its proper divisors (16880001).

21027375 is a wasteful number, since it uses less digits than its factorization.

21027375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18712 (or 18699 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 21027375 is about 4585.5615795669. The cubic root of 21027375 is about 276.0122474086.

Adding to 21027375 its reverse (57372012), we get a palindrome (78399387).

The spelling of 21027375 in words is "twenty-one million, twenty-seven thousand, three hundred seventy-five".