191789779122 has 54 divisors (see below), whose sum is σ = 419835163293. Its totient is φ = 63276524784.

The previous prime is 191789779099. The next prime is 191789779123. The reversal of 191789779122 is 221977987191.

It can be written as a sum of positive squares in 2 ways, for example, as 184033278081 + 7756501041 = 428991^2 + 88071^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=309669.

It is a self number, because there is not a number n which added to its sum of digits gives 191789779122.

It is not an unprimeable number, because it can be changed into a prime (191789779123) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 202523053 + ... + 202523999.

Almost surely, 2^191789779122 is an apocalyptic number.

191789779122 is an abundant number, since it is smaller than the sum of its proper divisors (228045384171).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191789779122 is an frugal number, since it uses more digits than its factorization.

191789779122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2120 (or 1061 counting only the distinct ones).

The product of its digits is 8001504, while the sum is 63.

The spelling of 191789779122 in words is "one hundred ninety-one billion, seven hundred eighty-nine million, seven hundred seventy-nine thousand, one hundred twenty-two".