191661059508 has 96 divisors (see below), whose sum is σ = 476659330560. Its totient is φ = 59830901760.

The previous prime is 191661059459. The next prime is 191661059509. The reversal of 191661059508 is 805950166191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191661059509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2429541 + ... + 2507187.

It is an arithmetic number, because the mean of its divisors is an integer number (4965201360).

Almost surely, 2^191661059508 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191661059508, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (238329665280).

191661059508 is an abundant number, since it is smaller than the sum of its proper divisors (284998271052).

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

191661059508 is a wasteful number, since it uses less digits than its factorization.

191661059508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77897 (or 77895 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 51.

The spelling of 191661059508 in words is "one hundred ninety-one billion, six hundred sixty-one million, fifty-nine thousand, five hundred eight".