191886138 has 16 divisors (see below), whose sum is σ = 426413760. Its totient is φ = 63962028.

The previous prime is 191886131. The next prime is 191886139. The reversal of 191886138 is 831688191.

191886138 is a `hidden beast` number, since 19 + 18 + 8 + 613 + 8 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 191886093 and 191886102.

It is not an unprimeable number, because it can be changed into a prime (191886131) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1776670 + ... + 1776777.

It is an arithmetic number, because the mean of its divisors is an integer number (26650860).

Almost surely, 2^191886138 is an apocalyptic number.

191886138 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

191886138 is an abundant number, since it is smaller than the sum of its proper divisors (234527622).

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

191886138 is a wasteful number, since it uses less digits than its factorization.

191886138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3553458 (or 3553452 counting only the distinct ones).

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

The square root of 191886138 is about 13852.2972102103. The cubic root of 191886138 is about 576.7857656971.

The spelling of 191886138 in words is "one hundred ninety-one million, eight hundred eighty-six thousand, one hundred thirty-eight".