21355606 has 16 divisors (see below), whose sum is σ = 32947200. Its totient is φ = 10375848.

The previous prime is 21355591. The next prime is 21355627. The reversal of 21355606 is 60655312.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 20035 + ... + 21073.

It is an arithmetic number, because the mean of its divisors is an integer number (2059200).

Almost surely, 2^21355606 is an apocalyptic number.

21355606 is a deficient number, since it is larger than the sum of its proper divisors (11591594).

21355606 is a wasteful number, since it uses less digits than its factorization.

21355606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 21355606 is about 4621.2126114257. The cubic root of 21355606 is about 277.4409949486.

The spelling of 21355606 in words is "twenty-one million, three hundred fifty-five thousand, six hundred six".