199978793042 has 54 divisors (see below), whose sum is σ = 352256641047. Its totient is φ = 84898858968.

The previous prime is 199978793029. The next prime is 199978793051. The reversal of 199978793042 is 240397879991.

199978793042 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 99989396521 + 99989396521 = 316211^2 + 316211^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=316211.

It is a super-2 number, since 2×199978793042² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

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 26 ways as a sum of consecutive naturals, for example, 880963733 + ... + 880963959.

Almost surely, 2^199978793042 is an apocalyptic number.

199978793042 is a deficient number, since it is larger than the sum of its proper divisors (152277848005).

199978793042 is an frugal number, since it uses more digits than its factorization.

199978793042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 868 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 61725888, while the sum is 68.

The spelling of 199978793042 in words is "one hundred ninety-nine billion, nine hundred seventy-eight million, seven hundred ninety-three thousand, forty-two".