20818945 has 8 divisors (see below), whose sum is σ = 28551744. Its totient is φ = 14275824.

The previous prime is 20818921. The next prime is 20818961. The reversal of 20818945 is 54981802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20818945 - 2¹¹ = 20816897 is a prime.

It is a Duffinian number.

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, 297379 + ... + 297448.

It is an arithmetic number, because the mean of its divisors is an integer number (3568968).

Almost surely, 2^20818945 is an apocalyptic number.

It is an amenable number.

20818945 is a deficient number, since it is larger than the sum of its proper divisors (7732799).

20818945 is an equidigital number, since it uses as much as digits as its factorization.

20818945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594839.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 20818945 is about 4562.7782106958. The cubic root of 20818945 is about 275.0972438461.

It can be divided in two parts, 2081 and 8945, that added together give a triangular number (11026 = T₁₄₈).

The spelling of 20818945 in words is "twenty million, eight hundred eighteen thousand, nine hundred forty-five".