191864 has 16 divisors (see below), whose sum is σ = 372600. Its totient is φ = 92512.

The previous prime is 191861. The next prime is 191899. The reversal of 191864 is 468191.

191864 = T₂₁₅ + T₂₁₆ + ... + T₂₂₂.

191864 is nontrivially palindromic in base 7.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191861) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 182 + ... + 645.

2¹⁹¹⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

191864 is a deficient number, since it is larger than the sum of its proper divisors (180736).

191864 is a wasteful number, since it uses less digits than its factorization.

191864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862 (or 858 counting only the distinct ones).

The product of its digits is 1728, while the sum is 29.

The square root of 191864 is about 438.0228304552. The cubic root of 191864 is about 57.6763583490.

The spelling of 191864 in words is "one hundred ninety-one thousand, eight hundred sixty-four".