1722989 has 2 divisors, whose sum is σ = 1722990. Its totient is φ = 1722988.

The previous prime is 1722983. The next prime is 1722991. The reversal of 1722989 is 9892271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1716100 + 6889 = 1310^2 + 83^2 .

It is an emirp because it is prime and its reverse (9892271) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1722989 is a prime.

Together with 1722991, 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 (1722983) 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, 861494 + 861495.

It is an arithmetic number, because the mean of its divisors is an integer number (861495).

2^1722989 is an apocalyptic number.

It is an amenable number.

1722989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1722989 is an equidigital number, since it uses as much as digits as its factorization.

1722989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 38.

The square root of 1722989 is about 1312.6267557840. The cubic root of 1722989 is about 119.8838923243.

The spelling of 1722989 in words is "one million, seven hundred twenty-two thousand, nine hundred eighty-nine".