21075306 has 32 divisors (see below), whose sum is σ = 48347520. Its totient is φ = 5999616.

The previous prime is 21075283. The next prime is 21075347. The reversal of 21075306 is 60357012.

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, 13410 + ... + 14898.

It is an arithmetic number, because the mean of its divisors is an integer number (1510860).

Almost surely, 2^21075306 is an apocalyptic number.

21075306 is an abundant number, since it is smaller than the sum of its proper divisors (27272214).

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

21075306 is a wasteful number, since it uses less digits than its factorization.

21075306 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1838.

The product of its (nonzero) digits is 1260, while the sum is 24.

The square root of 21075306 is about 4590.7849002104. The cubic root of 21075306 is about 276.2218076237.

The spelling of 21075306 in words is "twenty-one million, seventy-five thousand, three hundred six".