21068355 has 128 divisors (see below), whose sum is σ = 47278080. Its totient is φ = 7741440.

The previous prime is 21068339. The next prime is 21068357. The reversal of 21068355 is 55386012.

It is not a de Polignac number, because 21068355 - 2⁴ = 21068339 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21068357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 569397 + ... + 569433.

It is an arithmetic number, because the mean of its divisors is an integer number (369360).

Almost surely, 2^21068355 is an apocalyptic number.

21068355 is an abundant number, since it is smaller than the sum of its proper divisors (26209725).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21068355 is a wasteful number, since it uses less digits than its factorization.

21068355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 21068355 is about 4590.0277776937. The cubic root of 21068355 is about 276.1914367099.

The spelling of 21068355 in words is "twenty-one million, sixty-eight thousand, three hundred fifty-five".