19910986 has 16 divisors (see below), whose sum is σ = 30689280. Its totient is φ = 9683920.

The previous prime is 19910983. The next prime is 19910999. The reversal of 19910986 is 68901991.

It is not an unprimeable number, because it can be changed into a prime (19910983) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 17400 + ... + 18508.

It is an arithmetic number, because the mean of its divisors is an integer number (1918080).

Almost surely, 2^19910986 is an apocalyptic number.

19910986 is a deficient number, since it is larger than the sum of its proper divisors (10778294).

19910986 is a wasteful number, since it uses less digits than its factorization.

19910986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1349.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 19910986 is about 4462.1727891242. The cubic root of 19910986 is about 271.0384607931.

The spelling of 19910986 in words is "nineteen million, nine hundred ten thousand, nine hundred eighty-six".