997802209 has 2 divisors, whose sum is σ = 997802210. Its totient is φ = 997802208.

The previous prime is 997802207. The next prime is 997802231. The reversal of 997802209 is 902208799.

997802209 = T₂₅₇₉₀ + T₂₅₇₉₁ + T₂₅₇₉₂.

997802209 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., 657768609 + 340033600 = 25647^2 + 18440^2 .

It is a cyclic number.

It is not a de Polignac number, because 997802209 - 2¹ = 997802207 is a prime.

Together with 997802207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (997802203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498901104 + 498901105.

It is an arithmetic number, because the mean of its divisors is an integer number (498901105).

Almost surely, 2^997802209 is an apocalyptic number.

997802209 is the 25792-nd centered triangular number.

It is an amenable number.

997802209 is a deficient number, since it is larger than the sum of its proper divisors (1).

997802209 is an equidigital number, since it uses as much as digits as its factorization.

997802209 is an odious number, because the sum of its binary digits is odd.

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

The square root of 997802209 is about 31588.0073603892. The cubic root of 997802209 is about 999.2668656454.

The spelling of 997802209 in words is "nine hundred ninety-seven million, eight hundred two thousand, two hundred nine".