191661961344 has 256 divisors, whose sum is σ = 596929132800. Its totient is φ = 53343682560.

The previous prime is 191661961343. The next prime is 191661961349. The reversal of 191661961344 is 443169166191.

It is not an unprimeable number, because it can be changed into a prime (191661961343) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 134122422 + ... + 134123850.

It is an arithmetic number, because the mean of its divisors is an integer number (2331754425).

Almost surely, 2^191661961344 is an apocalyptic number.

191661961344 is a gapful number since it is divisible by the number (14) 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 191661961344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298464566400).

191661961344 is an abundant number, since it is smaller than the sum of its proper divisors (405267171456).

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

191661961344 is a wasteful number, since it uses less digits than its factorization.

191661961344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2711 (or 2699 counting only the distinct ones).

The product of its digits is 839808, while the sum is 51.

The spelling of 191661961344 in words is "one hundred ninety-one billion, six hundred sixty-one million, nine hundred sixty-one thousand, three hundred forty-four".