191138688 has 96 divisors (see below), whose sum is σ = 592377240. Its totient is φ = 58807296.

The previous prime is 191138677. The next prime is 191138693. The reversal of 191138688 is 886831191.

191138688 is a `hidden beast` number, since 191 + 1 + 386 + 88 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×191138688² = 73067996100722688, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8595 + ... + 21357.

Almost surely, 2^191138688 is an apocalyptic number.

191138688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191138688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (296188620).

191138688 is an abundant number, since it is smaller than the sum of its proper divisors (401238552).

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

191138688 is a wasteful number, since it uses less digits than its factorization.

191138688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12796 (or 12781 counting only the distinct ones).

The product of its digits is 82944, while the sum is 45.

The square root of 191138688 is about 13825.2916063279. The cubic root of 191138688 is about 576.0358773949.

The spelling of 191138688 in words is "one hundred ninety-one million, one hundred thirty-eight thousand, six hundred eighty-eight".