21190875 has 16 divisors (see below), whose sum is σ = 35262240. Its totient is φ = 11301600.

The previous prime is 21190867. The next prime is 21190879. The reversal of 21190875 is 57809112.

It is not a de Polignac number, because 21190875 - 2³ = 21190867 is a prime.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21190879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27880 + ... + 28629.

It is an arithmetic number, because the mean of its divisors is an integer number (2203890).

Almost surely, 2^21190875 is an apocalyptic number.

21190875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21190875 is a deficient number, since it is larger than the sum of its proper divisors (14071365).

21190875 is an equidigital number, since it uses as much as digits as its factorization.

21190875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56527 (or 56517 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 33.

The square root of 21190875 is about 4603.3547549586. The cubic root of 21190875 is about 276.7257861436.

Adding to 21190875 its reverse (57809112), we get a palindrome (78999987).

The spelling of 21190875 in words is "twenty-one million, one hundred ninety thousand, eight hundred seventy-five".