191434891 has 2 divisors, whose sum is σ = 191434892. Its totient is φ = 191434890.

The previous prime is 191434883. The next prime is 191434913. The reversal of 191434891 is 198434191.

It is a weak prime.

It is an emirp because it is prime and its reverse (198434191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191434891 - 2³ = 191434883 is a prime.

It is not a weakly prime, because it can be changed into another prime (191437891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95717445 + 95717446.

It is an arithmetic number, because the mean of its divisors is an integer number (95717446).

Almost surely, 2^191434891 is an apocalyptic number.

191434891 is a deficient number, since it is larger than the sum of its proper divisors (1).

191434891 is an equidigital number, since it uses as much as digits as its factorization.

191434891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 40.

The square root of 191434891 is about 13835.9998193119. Note that the first 3 decimals coincide. The cubic root of 191434891 is about 576.3332801090. Note that the first 3 decimals are identical.

The spelling of 191434891 in words is "one hundred ninety-one million, four hundred thirty-four thousand, eight hundred ninety-one".