391126987 has 2 divisors, whose sum is σ = 391126988. Its totient is φ = 391126986.

The previous prime is 391126961. The next prime is 391126999. The reversal of 391126987 is 789621193.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 391126987 - 2¹¹ = 391124939 is a prime.

It is not a weakly prime, because it can be changed into another prime (391126187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195563493 + 195563494.

It is an arithmetic number, because the mean of its divisors is an integer number (195563494).

Almost surely, 2^391126987 is an apocalyptic number.

391126987 is a deficient number, since it is larger than the sum of its proper divisors (1).

391126987 is an equidigital number, since it uses as much as digits as its factorization.

391126987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 163296, while the sum is 46.

The square root of 391126987 is about 19776.9306769276. The cubic root of 391126987 is about 731.3174352109.

The spelling of 391126987 in words is "three hundred ninety-one million, one hundred twenty-six thousand, nine hundred eighty-seven".