19979218546 has 24 divisors (see below), whose sum is σ = 34866599040. Its totient is φ = 8561318472.

The previous prime is 19979218543. The next prime is 19979218577. The reversal of 19979218546 is 64581297991.

It is not an unprimeable number, because it can be changed into a prime (19979218543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1276315 + ... + 1291873.

It is an arithmetic number, because the mean of its divisors is an integer number (1452774960).

Almost surely, 2^19979218546 is an apocalyptic number.

19979218546 is a deficient number, since it is larger than the sum of its proper divisors (14887380494).

19979218546 is a wasteful number, since it uses less digits than its factorization.

19979218546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28678 (or 28671 counting only the distinct ones).

The product of its digits is 9797760, while the sum is 61.

The spelling of 19979218546 in words is "nineteen billion, nine hundred seventy-nine million, two hundred eighteen thousand, five hundred forty-six".