20845566 has 32 divisors (see below), whose sum is σ = 52942080. Its totient is φ = 5955768.

The previous prime is 20845543. The next prime is 20845579. The reversal of 20845566 is 66554802.

20845566 is a `hidden beast` number, since 20 + 84 + 556 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 20845566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27196 + ... + 27951.

It is an arithmetic number, because the mean of its divisors is an integer number (1654440).

Almost surely, 2^20845566 is an apocalyptic number.

20845566 is an abundant number, since it is smaller than the sum of its proper divisors (32096514).

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

20845566 is a wasteful number, since it uses less digits than its factorization.

20845566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55165 (or 55159 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 20845566 is about 4565.6944707240. The cubic root of 20845566 is about 275.2144487045.

The spelling of 20845566 in words is "twenty million, eight hundred forty-five thousand, five hundred sixty-six".