20517866 has 8 divisors (see below), whose sum is σ = 31019520. Its totient is φ = 10178028.

The previous prime is 20517857. The next prime is 20517881. The reversal of 20517866 is 66871502.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40136 + ... + 40643.

It is an arithmetic number, because the mean of its divisors is an integer number (3877440).

Almost surely, 2^20517866 is an apocalyptic number.

20517866 is a deficient number, since it is larger than the sum of its proper divisors (10501654).

20517866 is a wasteful number, since it uses less digits than its factorization.

20517866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80908.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 20517866 is about 4529.6651090340. The cubic root of 20517866 is about 273.7646673125.

The spelling of 20517866 in words is "twenty million, five hundred seventeen thousand, eight hundred sixty-six".