997091971 has 2 divisors, whose sum is σ = 997091972. Its totient is φ = 997091970.

The previous prime is 997091969. The next prime is 997091989. The reversal of 997091971 is 179190799.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 997091971 - 2¹ = 997091969 is a prime.

Together with 997091969, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (997091941) 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, 498545985 + 498545986.

It is an arithmetic number, because the mean of its divisors is an integer number (498545986).

Almost surely, 2^997091971 is an apocalyptic number.

997091971 is a deficient number, since it is larger than the sum of its proper divisors (1).

997091971 is an equidigital number, since it uses as much as digits as its factorization.

997091971 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 321489, while the sum is 52.

The square root of 997091971 is about 31576.7631495060. The cubic root of 997091971 is about 999.0297158532.

The spelling of 997091971 in words is "nine hundred ninety-seven million, ninety-one thousand, nine hundred seventy-one".