1722656 has 48 divisors (see below), whose sum is σ = 3778488. Its totient is φ = 768000.

The previous prime is 1722653. The next prime is 1722667. The reversal of 1722656 is 6562271.

It can be written as a sum of positive squares in 4 ways, for example, as 1210000 + 512656 = 1100^2 + 716^2 .

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1722653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17006 + ... + 17106.

2^1722656 is an apocalyptic number.

1722656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is a pronic number, being equal to 1312×1313.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1722656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1889244).

1722656 is an abundant number, since it is smaller than the sum of its proper divisors (2055832).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1722656 is a wasteful number, since it uses less digits than its factorization.

1722656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 157 counting only the distinct ones).

The product of its digits is 5040, while the sum is 29.

The square root of 1722656 is about 1312.4999047619. The cubic root of 1722656 is about 119.8761685550.

It can be divided in two parts, 172265 and 6, that added together give a palindrome (172271).

The spelling of 1722656 in words is "one million, seven hundred twenty-two thousand, six hundred fifty-six".