191951 has 4 divisors (see below), whose sum is σ = 198600. Its totient is φ = 185304.

The previous prime is 191929. The next prime is 191953. The reversal of 191951 is 159191.

191951 = T₁₈ + T₁₉ + ... + T₁₀₄.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191951 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 191951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3281 + ... + 3338.

It is an arithmetic number, because the mean of its divisors is an integer number (49650).

2¹⁹¹⁹⁵¹ is an apocalyptic number.

191951 is a deficient number, since it is larger than the sum of its proper divisors (6649).

191951 is an equidigital number, since it uses as much as digits as its factorization.

191951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6648.

The product of its digits is 405, while the sum is 26.

The square root of 191951 is about 438.1221290919. The cubic root of 191951 is about 57.6850747400.

The spelling of 191951 in words is "one hundred ninety-one thousand, nine hundred fifty-one".