20818845 has 12 divisors (see below), whose sum is σ = 36086076. Its totient is φ = 11103360.

The previous prime is 20818789. The next prime is 20818859. The reversal of 20818845 is 54881802.

It can be written as a sum of positive squares in 2 ways, for example, as 15634116 + 5184729 = 3954^2 + 2277^2 .

It is not a de Polignac number, because 20818845 - 2⁹ = 20818333 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 231276 + ... + 231365.

It is an arithmetic number, because the mean of its divisors is an integer number (3007173).

Almost surely, 2^20818845 is an apocalyptic number.

It is an amenable number.

20818845 is a deficient number, since it is larger than the sum of its proper divisors (15267231).

20818845 is a wasteful number, since it uses less digits than its factorization.

20818845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462652 (or 462649 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 36.

The square root of 20818845 is about 4562.7672524467. The cubic root of 20818845 is about 275.0968033856.

The spelling of 20818845 in words is "twenty million, eight hundred eighteen thousand, eight hundred forty-five".