191971917316 has 27 divisors (see below), whose sum is σ = 340729502463. Its totient is φ = 94639536000.

The previous prime is 191971917209. The next prime is 191971917421. The reversal of 191971917316 is 613719179191.

It is a happy number.

The square root of 191971917316 is 438146.

It is a perfect power (a square), and thus also a powerful number.

191971917316 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 2140912900 + 189831004416 = 46270^2 + 435696^2 .

It is a super-2 number, since 2×191971917316² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 63967816 + ... + 63970816.

Almost surely, 2^191971917316 is an apocalyptic number.

191971917316 is the 438146-th square number.

It is an amenable number.

191971917316 is a deficient number, since it is larger than the sum of its proper divisors (148757585147).

191971917316 is an frugal number, since it uses more digits than its factorization.

191971917316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6152 (or 3076 counting only the distinct ones).

The product of its digits is 642978, while the sum is 55.

The spelling of 191971917316 in words is "one hundred ninety-one billion, nine hundred seventy-one million, nine hundred seventeen thousand, three hundred sixteen".