971787391 has 2 divisors, whose sum is σ = 971787392. Its totient is φ = 971787390.

The previous prime is 971787379. The next prime is 971787403. The reversal of 971787391 is 193787179.

It is a balanced prime because it is at equal distance from previous prime (971787379) and next prime (971787403).

It is a cyclic number.

It is not a de Polignac number, because 971787391 - 2⁷ = 971787263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (971787491) 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, 485893695 + 485893696.

It is an arithmetic number, because the mean of its divisors is an integer number (485893696).

Almost surely, 2^971787391 is an apocalyptic number.

971787391 is a deficient number, since it is larger than the sum of its proper divisors (1).

971787391 is an equidigital number, since it uses as much as digits as its factorization.

971787391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 666792, while the sum is 52.

The square root of 971787391 is about 31173.5046313372. The cubic root of 971787391 is about 990.5059451785.

The spelling of 971787391 in words is "nine hundred seventy-one million, seven hundred eighty-seven thousand, three hundred ninety-one".