1989973 has 2 divisors, whose sum is σ = 1989974. Its totient is φ = 1989972.

The previous prime is 1989961. The next prime is 1989979. The reversal of 1989973 is 3799891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1912689 + 77284 = 1383^2 + 278^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1989973 is a prime.

1989973 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1989979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994986 + 994987.

It is an arithmetic number, because the mean of its divisors is an integer number (994987).

2^1989973 is an apocalyptic number.

It is an amenable number.

1989973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1989973 is an equidigital number, since it uses as much as digits as its factorization.

1989973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 122472, while the sum is 46.

The square root of 1989973 is about 1410.6640280379. The cubic root of 1989973 is about 125.7811983295.

The spelling of 1989973 in words is "one million, nine hundred eighty-nine thousand, nine hundred seventy-three".