660971191 has 2 divisors, whose sum is σ = 660971192. Its totient is φ = 660971190.

The previous prime is 660971167. The next prime is 660971231. The reversal of 660971191 is 191179066.

It is an a-pointer prime, because the next prime (660971231) can be obtained adding 660971191 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 660971191 - 2⁷ = 660971063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660971141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330485595 + 330485596.

It is an arithmetic number, because the mean of its divisors is an integer number (330485596).

Almost surely, 2^660971191 is an apocalyptic number.

660971191 is a deficient number, since it is larger than the sum of its proper divisors (1).

660971191 is an equidigital number, since it uses as much as digits as its factorization.

660971191 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20412, while the sum is 40.

The square root of 660971191 is about 25709.3599881444. The cubic root of 660971191 is about 871.0856183820.

The spelling of 660971191 in words is "six hundred sixty million, nine hundred seventy-one thousand, one hundred ninety-one".