1689166901 has 2 divisors, whose sum is σ = 1689166902. Its totient is φ = 1689166900.

The previous prime is 1689166889. The next prime is 1689166951. The reversal of 1689166901 is 1096619861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1248208900 + 440958001 = 35330^2 + 20999^2 .

It is an emirp because it is prime and its reverse (1096619861) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1069916891 and 1986199601.

It is a cyclic number.

It is not a de Polignac number, because 1689166901 - 2²⁶ = 1622058037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1689166951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 844583450 + 844583451.

It is an arithmetic number, because the mean of its divisors is an integer number (844583451).

Almost surely, 2^1689166901 is an apocalyptic number.

It is an amenable number.

1689166901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1689166901 is an equidigital number, since it uses as much as digits as its factorization.

1689166901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 47.

The square root of 1689166901 is about 41099.4756779208. The cubic root of 1689166901 is about 1190.9426659586.

The spelling of 1689166901 in words is "one billion, six hundred eighty-nine million, one hundred sixty-six thousand, nine hundred one".