1197816989 has 2 divisors, whose sum is σ = 1197816990. Its totient is φ = 1197816988.

The previous prime is 1197816979. The next prime is 1197817001. The reversal of 1197816989 is 9896187911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 871725625 + 326091364 = 29525^2 + 18058^2 .

It is a cyclic number.

It is not a de Polignac number, because 1197816989 - 2²⁰ = 1196768413 is a prime.

It is a super-2 number, since 2×1197816989² = 2869531078274052242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1197816979) 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, 598908494 + 598908495.

It is an arithmetic number, because the mean of its divisors is an integer number (598908495).

Almost surely, 2^1197816989 is an apocalyptic number.

It is an amenable number.

1197816989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1197816989 is an equidigital number, since it uses as much as digits as its factorization.

1197816989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 59.

The square root of 1197816989 is about 34609.4927584904. The cubic root of 1197816989 is about 1062.0137904397.

The spelling of 1197816989 in words is "one billion, one hundred ninety-seven million, eight hundred sixteen thousand, nine hundred eighty-nine".