1720889 has 4 divisors (see below), whose sum is σ = 1780260. Its totient is φ = 1661520.

The previous prime is 1720867. The next prime is 1720897. The reversal of 1720889 is 9880271.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 466489 + 1254400 = 683^2 + 1120^2 .

It is a cyclic number.

It is not a de Polignac number, because 1720889 - 2⁸ = 1720633 is a prime.

It is a super-2 number, since 2×1720889² = 5922917900642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1720189) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29642 + ... + 29699.

It is an arithmetic number, because the mean of its divisors is an integer number (445065).

2^1720889 is an apocalyptic number.

It is an amenable number.

1720889 is a deficient number, since it is larger than the sum of its proper divisors (59371).

1720889 is an equidigital number, since it uses as much as digits as its factorization.

1720889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59370.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 1720889 is about 1311.8265891496. The cubic root of 1720889 is about 119.8351672068.

The spelling of 1720889 in words is "one million, seven hundred twenty thousand, eight hundred eighty-nine".