1997577689 has 2 divisors, whose sum is σ = 1997577690. Its totient is φ = 1997577688.

The previous prime is 1997577679. The next prime is 1997577713. The reversal of 1997577689 is 9867757991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1137915289 + 859662400 = 33733^2 + 29320^2 .

It is a cyclic number.

It is not a de Polignac number, because 1997577689 - 2⁸ = 1997577433 is a prime.

It is not a weakly prime, because it can be changed into another prime (1997577679) 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, 998788844 + 998788845.

It is an arithmetic number, because the mean of its divisors is an integer number (998788845).

Almost surely, 2^1997577689 is an apocalyptic number.

It is an amenable number.

1997577689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997577689 is an equidigital number, since it uses as much as digits as its factorization.

1997577689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60011280, while the sum is 68.

The square root of 1997577689 is about 44694.2690845258. The cubic root of 1997577689 is about 1259.4121909674.

The spelling of 1997577689 in words is "one billion, nine hundred ninety-seven million, five hundred seventy-seven thousand, six hundred eighty-nine".