157811191 has 2 divisors, whose sum is σ = 157811192. Its totient is φ = 157811190.

The previous prime is 157811189. The next prime is 157811239. The reversal of 157811191 is 191118751.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 157811191 - 2¹ = 157811189 is a prime.

Together with 157811189, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157811491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78905595 + 78905596.

It is an arithmetic number, because the mean of its divisors is an integer number (78905596).

Almost surely, 2^157811191 is an apocalyptic number.

157811191 is a deficient number, since it is larger than the sum of its proper divisors (1).

157811191 is an equidigital number, since it uses as much as digits as its factorization.

157811191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 34.

The square root of 157811191 is about 12562.2924261458. The cubic root of 157811191 is about 540.3965890939.

It can be divided in two parts, 1578 and 11191, that added together give a square (12769 = 113²).

The spelling of 157811191 in words is "one hundred fifty-seven million, eight hundred eleven thousand, one hundred ninety-one".