20999986 has 16 divisors (see below), whose sum is σ = 36175680. Its totient is φ = 8956080.

The previous prime is 20999977. The next prime is 20999999. The reversal of 20999986 is 68999902.

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, 601 + ... + 6508.

It is an arithmetic number, because the mean of its divisors is an integer number (2260980).

Almost surely, 2^20999986 is an apocalyptic number.

20999986 is a deficient number, since it is larger than the sum of its proper divisors (15175694).

20999986 is a wasteful number, since it uses less digits than its factorization.

20999986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7329.

The product of its (nonzero) digits is 629856, while the sum is 52.

The square root of 20999986 is about 4582.5741674304. The cubic root of 20999986 is about 275.8923563287.

The spelling of 20999986 in words is "twenty million, nine hundred ninety-nine thousand, nine hundred eighty-six".