1640168989 has 2 divisors, whose sum is σ = 1640168990. Its totient is φ = 1640168988.

The previous prime is 1640168953. The next prime is 1640169029. The reversal of 1640168989 is 9898610461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1220943364 + 419225625 = 34942^2 + 20475^2 .

It is a cyclic number.

It is not a de Polignac number, because 1640168989 - 2⁷ = 1640168861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640162989) 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, 820084494 + 820084495.

It is an arithmetic number, because the mean of its divisors is an integer number (820084495).

Almost surely, 2^1640168989 is an apocalyptic number.

It is an amenable number.

1640168989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640168989 is an equidigital number, since it uses as much as digits as its factorization.

1640168989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 746496, while the sum is 52.

The square root of 1640168989 is about 40498.9998518482. Note that the first 3 decimals coincide. The cubic root of 1640168989 is about 1179.3142115388.

The spelling of 1640168989 in words is "one billion, six hundred forty million, one hundred sixty-eight thousand, nine hundred eighty-nine".