191668591957 has 8 divisors (see below), whose sum is σ = 192745024472. Its totient is φ = 190592352000.

The previous prime is 191668591903. The next prime is 191668591973. The reversal of 191668591957 is 759195866191.

It can be written as a sum of positive squares in 4 ways, for example, as 26894596 + 191641697361 = 5186^2 + 437769^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 191668591957 - 2³⁵ = 157308853589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 191668591892 and 191668591901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191668591657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2256457 + ... + 2339857.

It is an arithmetic number, because the mean of its divisors is an integer number (24093128059).

Almost surely, 2^191668591957 is an apocalyptic number.

It is an amenable number.

191668591957 is a deficient number, since it is larger than the sum of its proper divisors (1076432515).

191668591957 is a wasteful number, since it uses less digits than its factorization.

191668591957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96279.

The product of its digits is 36741600, while the sum is 67.

The spelling of 191668591957 in words is "one hundred ninety-one billion, six hundred sixty-eight million, five hundred ninety-one thousand, nine hundred fifty-seven".