1721722 has 4 divisors (see below), whose sum is σ = 2582586. Its totient is φ = 860860.

The previous prime is 1721719. The next prime is 1721729. The reversal of 1721722 is 2271271.

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

It can be written as a sum of positive squares in only one way, i.e., 1190281 + 531441 = 1091^2 + 729^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1721693 and 1721702.

It is not an unprimeable number, because it can be changed into a prime (1721729) 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, 430429 + ... + 430432.

2^1721722 is an apocalyptic number.

1721722 is a deficient number, since it is larger than the sum of its proper divisors (860864).

1721722 is an equidigital number, since it uses as much as digits as its factorization.

1721722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860863.

The product of its digits is 392, while the sum is 22.

The square root of 1721722 is about 1312.1440469705. The cubic root of 1721722 is about 119.8544995775.

Adding to 1721722 its reverse (2271271), we get a palindrome (3992993).

The spelling of 1721722 in words is "one million, seven hundred twenty-one thousand, seven hundred twenty-two".