1997189 has 2 divisors, whose sum is σ = 1997190. Its totient is φ = 1997188.

The previous prime is 1997183. The next prime is 1997213. The reversal of 1997189 is 9817991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1288225 + 708964 = 1135^2 + 842^2 .

It is an emirp because it is prime and its reverse (9817991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1997189 - 2⁴ = 1997173 is a prime.

It is a plaindrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1997183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 998594 + 998595.

It is an arithmetic number, because the mean of its divisors is an integer number (998595).

2^1997189 is an apocalyptic number.

It is an amenable number.

1997189 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997189 is an equidigital number, since it uses as much as digits as its factorization.

1997189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 44.

The square root of 1997189 is about 1413.2193743365. The cubic root of 1997189 is about 125.9330500124.

The spelling of 1997189 in words is "one million, nine hundred ninety-seven thousand, one hundred eighty-nine".