191390387 has 2 divisors, whose sum is σ = 191390388. Its totient is φ = 191390386.

The previous prime is 191390371. The next prime is 191390393. The reversal of 191390387 is 783093191.

191390387 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 191390387 - 2⁴ = 191390371 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (191390357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95695193 + 95695194.

It is an arithmetic number, because the mean of its divisors is an integer number (95695194).

Almost surely, 2^191390387 is an apocalyptic number.

191390387 is a deficient number, since it is larger than the sum of its proper divisors (1).

191390387 is an equidigital number, since it uses as much as digits as its factorization.

191390387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 191390387 is about 13834.3914575235. The cubic root of 191390387 is about 576.2886154469.

The spelling of 191390387 in words is "one hundred ninety-one million, three hundred ninety thousand, three hundred eighty-seven".