19979218 has 16 divisors (see below), whose sum is σ = 35086464. Its totient is φ = 8353440.

The previous prime is 19979213. The next prime is 19979227. The reversal of 19979218 is 81297991.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (19979213) 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, 16830 + ... + 17977.

It is an arithmetic number, because the mean of its divisors is an integer number (2192904).

Almost surely, 2^19979218 is an apocalyptic number.

19979218 is a deficient number, since it is larger than the sum of its proper divisors (15107246).

19979218 is a wasteful number, since it uses less digits than its factorization.

19979218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34857.

The product of its digits is 81648, while the sum is 46.

The square root of 19979218 is about 4469.8118528636. The cubic root of 19979218 is about 271.3477106977.

The spelling of 19979218 in words is "nineteen million, nine hundred seventy-nine thousand, two hundred eighteen".