191911668 has 72 divisors (see below), whose sum is σ = 488583648. Its totient is φ = 58601088.

The previous prime is 191911667. The next prime is 191911697. The reversal of 191911668 is 866119191.

It is a happy number.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191911667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 350571 + ... + 351117.

It is an arithmetic number, because the mean of its divisors is an integer number (6785884).

Almost surely, 2^191911668 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 191911668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (244291824).

191911668 is an abundant number, since it is smaller than the sum of its proper divisors (296671980).

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

191911668 is a wasteful number, since it uses less digits than its factorization.

191911668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753 (or 738 counting only the distinct ones).

The product of its digits is 23328, while the sum is 42.

The square root of 191911668 is about 13853.2186873665. The cubic root of 191911668 is about 576.8113445599.

The spelling of 191911668 in words is "one hundred ninety-one million, nine hundred eleven thousand, six hundred sixty-eight".