19959986 has 4 divisors (see below), whose sum is σ = 29939982. Its totient is φ = 9979992.

The previous prime is 19959977. The next prime is 19960009. The reversal of 19959986 is 68995991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12567025 + 7392961 = 3545^2 + 2719^2 .

It is a super-2 number, since 2×19959986² = 796802082240392, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989995 + ... + 4989998.

Almost surely, 2^19959986 is an apocalyptic number.

19959986 is a deficient number, since it is larger than the sum of its proper divisors (9979996).

19959986 is an equidigital number, since it uses as much as digits as its factorization.

19959986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9979995.

The product of its digits is 1574640, while the sum is 56.

The square root of 19959986 is about 4467.6600139223. The cubic root of 19959986 is about 271.2606162890.

The spelling of 19959986 in words is "nineteen million, nine hundred fifty-nine thousand, nine hundred eighty-six".