997706989 has 2 divisors, whose sum is σ = 997706990. Its totient is φ = 997706988.

The previous prime is 997706953. The next prime is 997706993. The reversal of 997706989 is 989607799.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 920090889 + 77616100 = 30333^2 + 8810^2 .

It is a cyclic number.

It is not a de Polignac number, because 997706989 - 2⁷ = 997706861 is a prime.

It is a super-2 number, since 2×997706989² = 1990838471798892242, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 997706989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997706939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498853494 + 498853495.

It is an arithmetic number, because the mean of its divisors is an integer number (498853495).

Almost surely, 2^997706989 is an apocalyptic number.

It is an amenable number.

997706989 is a deficient number, since it is larger than the sum of its proper divisors (1).

997706989 is an equidigital number, since it uses as much as digits as its factorization.

997706989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15431472, while the sum is 64.

The square root of 997706989 is about 31586.5001068494. The cubic root of 997706989 is about 999.2350780436.

The spelling of 997706989 in words is "nine hundred ninety-seven million, seven hundred six thousand, nine hundred eighty-nine".