191945 has 8 divisors (see below), whose sum is σ = 248136. Its totient is φ = 141696.

The previous prime is 191929. The next prime is 191953. The reversal of 191945 is 549191.

191945 = 19² + 20² + ... + 83².

It can be written as a sum of positive squares in 4 ways, for example, as 16384 + 175561 = 128^2 + 419^2 .

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 191945 - 2⁴ = 191929 is a prime.

It is a Duffinian number.

It is a Curzon 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 7 ways as a sum of consecutive naturals, for example, 1412 + ... + 1541.

It is an arithmetic number, because the mean of its divisors is an integer number (31017).

2¹⁹¹⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

191945 is a deficient number, since it is larger than the sum of its proper divisors (56191).

191945 is a wasteful number, since it uses less digits than its factorization.

191945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2971.

The product of its digits is 1620, while the sum is 29.

The square root of 191945 is about 438.1152816326. The cubic root of 191945 is about 57.6844736941.

The spelling of 191945 in words is "one hundred ninety-one thousand, nine hundred forty-five".