1989161 has 2 divisors, whose sum is σ = 1989162. Its totient is φ = 1989160.

The previous prime is 1989151. The next prime is 1989193. The reversal of 1989161 is 1619891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1142761 + 846400 = 1069^2 + 920^2 .

It is a cyclic number.

It is not a de Polignac number, because 1989161 - 2¹⁰ = 1988137 is a prime.

It is a super-2 number, since 2×1989161² = 7913522967842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1989101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994580 + 994581.

It is an arithmetic number, because the mean of its divisors is an integer number (994581).

2^1989161 is an apocalyptic number.

It is an amenable number.

1989161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989161 is an equidigital number, since it uses as much as digits as its factorization.

1989161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 35.

The square root of 1989161 is about 1410.3761909505. The cubic root of 1989161 is about 125.7640878414.

The spelling of 1989161 in words is "one million, nine hundred eighty-nine thousand, one hundred sixty-one".