20806644 has 24 divisors (see below), whose sum is σ = 48798400. Its totient is φ = 6899904.

The previous prime is 20806637. The next prime is 20806661. The reversal of 20806644 is 44660802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1969 + ... + 6744.

Almost surely, 2^20806644 is an apocalyptic number.

It is an amenable number.

20806644 is an abundant number, since it is smaller than the sum of its proper divisors (27991756).

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

20806644 is a wasteful number, since it uses less digits than its factorization.

20806644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8919 (or 8917 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 20806644 is about 4561.4300389242. The cubic root of 20806644 is about 275.0430522128.

The spelling of 20806644 in words is "twenty million, eight hundred six thousand, six hundred forty-four".