21506682 has 16 divisors (see below), whose sum is σ = 43068672. Its totient is φ = 7159680.

The previous prime is 21506669. The next prime is 21506707. The reversal of 21506682 is 28660512.

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 7 ways as a sum of consecutive naturals, for example, 4138 + ... + 7754.

It is an arithmetic number, because the mean of its divisors is an integer number (2691792).

Almost surely, 2^21506682 is an apocalyptic number.

21506682 is an abundant number, since it is smaller than the sum of its proper divisors (21561990).

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

21506682 is a wasteful number, since it uses less digits than its factorization.

21506682 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4613.

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 21506682 is about 4637.5297303629. The cubic root of 21506682 is about 278.0936920025.

The spelling of 21506682 in words is "twenty-one million, five hundred six thousand, six hundred eighty-two".