19979986 has 8 divisors (see below), whose sum is σ = 32275404. Its totient is φ = 9221520.

The previous prime is 19979959. The next prime is 19979987. The reversal of 19979986 is 68997991.

It can be written as a sum of positive squares in 2 ways, for example, as 18224361 + 1755625 = 4269^2 + 1325^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 19979986.

It is not an unprimeable number, because it can be changed into a prime (19979987) 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 3 ways as a sum of consecutive naturals, for example, 384205 + ... + 384256.

Almost surely, 2^19979986 is an apocalyptic number.

19979986 is a deficient number, since it is larger than the sum of its proper divisors (12295418).

19979986 is a wasteful number, since it uses less digits than its factorization.

19979986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768476.

The product of its digits is 2204496, while the sum is 58.

The square root of 19979986 is about 4469.8977616943. The cubic root of 19979986 is about 271.3511875166.

The spelling of 19979986 in words is "nineteen million, nine hundred seventy-nine thousand, nine hundred eighty-six".