213540191 has 2 divisors, whose sum is σ = 213540192. Its totient is φ = 213540190.

The previous prime is 213540169. The next prime is 213540203. The reversal of 213540191 is 191045312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213540191 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213540191.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213540991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106770095 + 106770096.

It is an arithmetic number, because the mean of its divisors is an integer number (106770096).

Almost surely, 2^213540191 is an apocalyptic number.

213540191 is a deficient number, since it is larger than the sum of its proper divisors (1).

213540191 is an equidigital number, since it uses as much as digits as its factorization.

213540191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 213540191 is about 14613.0144391908. The cubic root of 213540191 is about 597.7136981797.

The spelling of 213540191 in words is "two hundred thirteen million, five hundred forty thousand, one hundred ninety-one".