1669221689 has 2 divisors, whose sum is σ = 1669221690. Its totient is φ = 1669221688.

The previous prime is 1669221683. The next prime is 1669221703. The reversal of 1669221689 is 9861229661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 905528464 + 763693225 = 30092^2 + 27635^2 .

It is a cyclic number.

It is not a de Polignac number, because 1669221689 - 2²⁰ = 1668173113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1669221683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834610844 + 834610845.

It is an arithmetic number, because the mean of its divisors is an integer number (834610845).

Almost surely, 2^1669221689 is an apocalyptic number.

It is an amenable number.

1669221689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669221689 is an equidigital number, since it uses as much as digits as its factorization.

1669221689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 50.

The square root of 1669221689 is about 40856.1095676032. The cubic root of 1669221689 is about 1186.2366549502.

The spelling of 1669221689 in words is "one billion, six hundred sixty-nine million, two hundred twenty-one thousand, six hundred eighty-nine".