21075366 has 32 divisors (see below), whose sum is σ = 45708768. Its totient is φ = 6439680.

The previous prime is 21075349. The next prime is 21075371. The reversal of 21075366 is 66357012.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 11386 + ... + 13106.

It is an arithmetic number, because the mean of its divisors is an integer number (1428399).

Almost surely, 2^21075366 is an apocalyptic number.

21075366 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21075366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22854384).

21075366 is an abundant number, since it is smaller than the sum of its proper divisors (24633402).

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

21075366 is a wasteful number, since it uses less digits than its factorization.

21075366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1896.

The product of its (nonzero) digits is 7560, while the sum is 30.

The square root of 21075366 is about 4590.7914350360. The cubic root of 21075366 is about 276.2220697518. Note that the first 3 decimals are identical.

The spelling of 21075366 in words is "twenty-one million, seventy-five thousand, three hundred sixty-six".