191591632872 has 24 divisors (see below), whose sum is σ = 518894005890. Its totient is φ = 63863877600.

The previous prime is 191591632861. The next prime is 191591632943. The reversal of 191591632872 is 278236195191.

It is a happy number.

191591632872 is a `hidden beast` number, since 19 + 1 + 591 + 6 + 32 + 8 + 7 + 2 = 666.

191591632872 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 only one way, i.e., 175287918276 + 16303714596 = 418674^2 + 127686^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-3 number, since 3×191591632872³ (a number of 35 digits) contains 333 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 5 ways as a sum of consecutive naturals, for example, 1330497379 + ... + 1330497522.

Almost surely, 2^191591632872 is an apocalyptic number.

191591632872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

191591632872 is an abundant number, since it is smaller than the sum of its proper divisors (327302373018).

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

191591632872 is a wasteful number, since it uses less digits than its factorization.

191591632872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2660994913 (or 2660994906 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 54.

The spelling of 191591632872 in words is "one hundred ninety-one billion, five hundred ninety-one million, six hundred thirty-two thousand, eight hundred seventy-two".