191596978580 has 144 divisors (see below), whose sum is σ = 470620659600. Its totient is φ = 65330012160.

The previous prime is 191596978577. The next prime is 191596978609. The reversal of 191596978580 is 85879695191.

It can be written as a sum of positive squares in 8 ways, for example, as 58376358544 + 133220620036 = 241612^2 + 364994^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 191596978580.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 206239556 + ... + 206240484.

It is an arithmetic number, because the mean of its divisors is an integer number (3268199025).

Almost surely, 2^191596978580 is an apocalyptic number.

191596978580 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191596978580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235310329800).

191596978580 is an abundant number, since it is smaller than the sum of its proper divisors (279023681020).

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

191596978580 is a wasteful number, since it uses less digits than its factorization.

191596978580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1882 (or 1873 counting only the distinct ones).

The product of its (nonzero) digits is 48988800, while the sum is 68.

The spelling of 191596978580 in words is "one hundred ninety-one billion, five hundred ninety-six million, nine hundred seventy-eight thousand, five hundred eighty".