971787491 has 2 divisors, whose sum is σ = 971787492. Its totient is φ = 971787490.

The previous prime is 971787469. The next prime is 971787493. The reversal of 971787491 is 194787179.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 971787491 - 2¹⁰ = 971786467 is a prime.

Together with 971787493, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (971787493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 485893745 + 485893746.

It is an arithmetic number, because the mean of its divisors is an integer number (485893746).

Almost surely, 2^971787491 is an apocalyptic number.

971787491 is a deficient number, since it is larger than the sum of its proper divisors (1).

971787491 is an equidigital number, since it uses as much as digits as its factorization.

971787491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 889056, while the sum is 53.

The square root of 971787491 is about 31173.5062352633. The cubic root of 971787491 is about 990.5059791539.

The spelling of 971787491 in words is "nine hundred seventy-one million, seven hundred eighty-seven thousand, four hundred ninety-one".