191956665556 has 36 divisors (see below), whose sum is σ = 357310319548. Its totient is φ = 90164116224.

The previous prime is 191956665547. The next prime is 191956665557. The reversal of 191956665556 is 655566659191.

It can be written as a sum of positive squares in 6 ways, for example, as 20187863056 + 171768802500 = 142084^2 + 414450^2 .

It is a super-2 number, since 2×191956665556² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191956665557) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 646641 + ... + 895576.

Almost surely, 2^191956665556 is an apocalyptic number.

It is an amenable number.

191956665556 is a deficient number, since it is larger than the sum of its proper divisors (165353653992).

191956665556 is a wasteful number, since it uses less digits than its factorization.

191956665556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1542316 (or 1542285 counting only the distinct ones).

The product of its digits is 65610000, while the sum is 64.

The spelling of 191956665556 in words is "one hundred ninety-one billion, nine hundred fifty-six million, six hundred sixty-five thousand, five hundred fifty-six".