20919986 has 8 divisors (see below), whose sum is σ = 31399680. Its totient is φ = 10453428.

The previous prime is 20919967. The next prime is 20920019. The reversal of 20919986 is 68991902.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3515 + ... + 7361.

It is an arithmetic number, because the mean of its divisors is an integer number (3924960).

Almost surely, 2^20919986 is an apocalyptic number.

20919986 is a deficient number, since it is larger than the sum of its proper divisors (10479694).

20919986 is a wasteful number, since it uses less digits than its factorization.

20919986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6568.

The product of its (nonzero) digits is 69984, while the sum is 44.

The square root of 20919986 is about 4573.8371199683. The cubic root of 20919986 is about 275.5415707749.

The spelling of 20919986 in words is "twenty million, nine hundred nineteen thousand, nine hundred eighty-six".