1669138849 has 16 divisors (see below), whose sum is σ = 1930139008. Its totient is φ = 1413821952.

The previous prime is 1669138843. The next prime is 1669138873. The reversal of 1669138849 is 9488319661.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1669138849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1669138849.

It is not an unprimeable number, because it can be changed into a prime (1669138843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 594082 + ... + 596884.

It is an arithmetic number, because the mean of its divisors is an integer number (120633688).

Almost surely, 2^1669138849 is an apocalyptic number.

It is an amenable number.

1669138849 is a deficient number, since it is larger than the sum of its proper divisors (261000159).

1669138849 is an equidigital number, since it uses as much as digits as its factorization.

1669138849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3784.

The product of its digits is 2239488, while the sum is 55.

The square root of 1669138849 is about 40855.0957531616. The cubic root of 1669138849 is about 1186.2170311397.

The spelling of 1669138849 in words is "one billion, six hundred sixty-nine million, one hundred thirty-eight thousand, eight hundred forty-nine".