1668513109 has 2 divisors, whose sum is σ = 1668513110. Its totient is φ = 1668513108.

The previous prime is 1668513083. The next prime is 1668513137. The reversal of 1668513109 is 9013158661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1162128100 + 506385009 = 34090^2 + 22503^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668513109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1668519109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834256554 + 834256555.

It is an arithmetic number, because the mean of its divisors is an integer number (834256555).

Almost surely, 2^1668513109 is an apocalyptic number.

It is an amenable number.

1668513109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668513109 is an equidigital number, since it uses as much as digits as its factorization.

1668513109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 1668513109 is about 40847.4369942595. The cubic root of 1668513109 is about 1186.0687797984.

The spelling of 1668513109 in words is "one billion, six hundred sixty-eight million, five hundred thirteen thousand, one hundred nine".