191243887 has 8 divisors (see below), whose sum is σ = 193450752. Its totient is φ = 189048600.

The previous prime is 191243851. The next prime is 191243903. The reversal of 191243887 is 788342191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 191243887 - 2²³ = 182855279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191243587) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32808 + ... + 38194.

It is an arithmetic number, because the mean of its divisors is an integer number (24181344).

Almost surely, 2^191243887 is an apocalyptic number.

191243887 is a deficient number, since it is larger than the sum of its proper divisors (2206865).

191243887 is a wasteful number, since it uses less digits than its factorization.

191243887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5789.

The product of its digits is 96768, while the sum is 43.

The square root of 191243887 is about 13829.0956681918. The cubic root of 191243887 is about 576.1415376442.

The spelling of 191243887 in words is "one hundred ninety-one million, two hundred forty-three thousand, eight hundred eighty-seven".