1809289991669 has 2 divisors, whose sum is σ = 1809289991670. Its totient is φ = 1809289991668.

The previous prime is 1809289991657. The next prime is 1809289991699. The reversal of 1809289991669 is 9661999829081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1466932768900 + 342357222769 = 1211170^2 + 585113^2 .

It is a cyclic number.

It is not a de Polignac number, because 1809289991669 - 2²⁴ = 1809273214453 is a prime.

It is a super-2 number, since 2×1809289991669² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1809289991669.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1809289991609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 904644995834 + 904644995835.

It is an arithmetic number, because the mean of its divisors is an integer number (904644995835).

Almost surely, 2^{1809289991669} is an apocalyptic number.

It is an amenable number.

1809289991669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1809289991669 is an equidigital number, since it uses as much as digits as its factorization.

1809289991669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 272097792, while the sum is 77.

The spelling of 1809289991669 in words is "one trillion, eight hundred nine billion, two hundred eighty-nine million, nine hundred ninety-one thousand, six hundred sixty-nine".