191890213 has 2 divisors, whose sum is σ = 191890214. Its totient is φ = 191890212.

The previous prime is 191890189. The next prime is 191890247. The reversal of 191890213 is 312098191.

It is an a-pointer prime, because the next prime (191890247) can be obtained adding 191890213 to its sum of digits (34).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168532324 + 23357889 = 12982^2 + 4833^2 .

It is a cyclic number.

It is not a de Polignac number, because 191890213 - 2⁹ = 191889701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191890313) 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 as a sum of consecutive naturals, namely, 95945106 + 95945107.

It is an arithmetic number, because the mean of its divisors is an integer number (95945107).

Almost surely, 2^191890213 is an apocalyptic number.

It is an amenable number.

191890213 is a deficient number, since it is larger than the sum of its proper divisors (1).

191890213 is an equidigital number, since it uses as much as digits as its factorization.

191890213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 34.

The square root of 191890213 is about 13852.4442969463. Note that the first 3 decimals coincide. The cubic root of 191890213 is about 576.7898486485.

The spelling of 191890213 in words is "one hundred ninety-one million, eight hundred ninety thousand, two hundred thirteen".