191954891 has 6 divisors (see below), whose sum is σ = 202589892. Its totient is φ = 181851660.

The previous prime is 191954869. The next prime is 191954921. The reversal of 191954891 is 198459191.

It is not a de Polignac number, because 191954891 - 2⁶ = 191954827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191954291) 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 5 ways as a sum of consecutive naturals, for example, 265505 + ... + 266226.

It is an arithmetic number, because the mean of its divisors is an integer number (33764982).

Almost surely, 2^191954891 is an apocalyptic number.

191954891 is a deficient number, since it is larger than the sum of its proper divisors (10635001).

191954891 is an equidigital number, since it uses as much as digits as its factorization.

191954891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531769 (or 531750 counting only the distinct ones).

The product of its digits is 116640, while the sum is 47.

The square root of 191954891 is about 13854.7786341031. The cubic root of 191954891 is about 576.8546451150.

The spelling of 191954891 in words is "one hundred ninety-one million, nine hundred fifty-four thousand, eight hundred ninety-one".