191691794516 has 6 divisors (see below), whose sum is σ = 335460640410. Its totient is φ = 95845897256.

The previous prime is 191691794513. The next prime is 191691794531. The reversal of 191691794516 is 615497196191.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 108205470916 + 83486323600 = 328946^2 + 288940^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191691794513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 23961474311 + ... + 23961474318.

It is an arithmetic number, because the mean of its divisors is an integer number (55910106735).

Almost surely, 2^191691794516 is an apocalyptic number.

It is an amenable number.

191691794516 is a deficient number, since it is larger than the sum of its proper divisors (143768845894).

191691794516 is a wasteful number, since it uses less digits than its factorization.

191691794516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47922948633 (or 47922948631 counting only the distinct ones).

The product of its digits is 3674160, while the sum is 59.

The spelling of 191691794516 in words is "one hundred ninety-one billion, six hundred ninety-one million, seven hundred ninety-four thousand, five hundred sixteen".