1791989 has 2 divisors, whose sum is σ = 1791990. Its totient is φ = 1791988.

The previous prime is 1791973. The next prime is 1791991. The reversal of 1791989 is 9891971.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 917764 + 874225 = 958^2 + 935^2 .

It is a cyclic number.

It is not a de Polignac number, because 1791989 - 2⁴ = 1791973 is a prime.

It is a super-2 number, since 2×1791989² = 6422449152242, which contains 22 as substring.

Together with 1791991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1791089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 895994 + 895995.

It is an arithmetic number, because the mean of its divisors is an integer number (895995).

2^1791989 is an apocalyptic number.

It is an amenable number.

1791989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1791989 is an equidigital number, since it uses as much as digits as its factorization.

1791989 is an odious number, because the sum of its binary digits is odd.

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

The square root of 1791989 is about 1338.6519338499. The cubic root of 1791989 is about 121.4633103442.

The spelling of 1791989 in words is "one million, seven hundred ninety-one thousand, nine hundred eighty-nine".