21068187 has 24 divisors (see below), whose sum is σ = 32864832. Its totient is φ = 11970000.

The previous prime is 21068183. The next prime is 21068209. The reversal of 21068187 is 78186012.

It is a happy number.

It is not a de Polignac number, because 21068187 - 2² = 21068183 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21068183) 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 23 ways as a sum of consecutive naturals, for example, 36612 + ... + 37182.

It is an arithmetic number, because the mean of its divisors is an integer number (1369368).

Almost surely, 2^21068187 is an apocalyptic number.

21068187 is a deficient number, since it is larger than the sum of its proper divisors (11796645).

21068187 is a wasteful number, since it uses less digits than its factorization.

21068187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 839 (or 832 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 33.

The square root of 21068187 is about 4590.0094771144. The cubic root of 21068187 is about 276.1907025870.

The spelling of 21068187 in words is "twenty-one million, sixty-eight thousand, one hundred eighty-seven".