391115287 has 2 divisors, whose sum is σ = 391115288. Its totient is φ = 391115286.

The previous prime is 391115273. The next prime is 391115317. The reversal of 391115287 is 782511193.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 391115287 - 2⁷ = 391115159 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (391115267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195557643 + 195557644.

It is an arithmetic number, because the mean of its divisors is an integer number (195557644).

Almost surely, 2^391115287 is an apocalyptic number.

391115287 is a deficient number, since it is larger than the sum of its proper divisors (1).

391115287 is an equidigital number, since it uses as much as digits as its factorization.

391115287 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 37.

The square root of 391115287 is about 19776.6348755293. The cubic root of 391115287 is about 731.3101430359.

The spelling of 391115287 in words is "three hundred ninety-one million, one hundred fifteen thousand, two hundred eighty-seven".