997491757 has 2 divisors, whose sum is σ = 997491758. Its totient is φ = 997491756.

The previous prime is 997491749. The next prime is 997491953. The reversal of 997491757 is 757194799.

997491757 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 813048196 + 184443561 = 28514^2 + 13581^2 .

It is a cyclic number.

It is not a de Polignac number, because 997491757 - 2³ = 997491749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997491707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498745878 + 498745879.

It is an arithmetic number, because the mean of its divisors is an integer number (498745879).

Almost surely, 2^997491757 is an apocalyptic number.

It is an amenable number.

997491757 is a deficient number, since it is larger than the sum of its proper divisors (1).

997491757 is an equidigital number, since it uses as much as digits as its factorization.

997491757 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5000940, while the sum is 58.

The square root of 997491757 is about 31583.0928979415. The cubic root of 997491757 is about 999.1632189929.

The spelling of 997491757 in words is "nine hundred ninety-seven million, four hundred ninety-one thousand, seven hundred fifty-seven".