1722816 has 56 divisors (see below), whose sum is σ = 5069840. Its totient is φ = 573696.

The previous prime is 1722793. The next prime is 1722821. The reversal of 1722816 is 6182271.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 1722816.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1230 + ... + 2226.

2^1722816 is an apocalyptic number.

1722816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1722816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2534920).

1722816 is an abundant number, since it is smaller than the sum of its proper divisors (3347024).

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

1722816 is an equidigital number, since it uses as much as digits as its factorization.

1722816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1018 (or 1002 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 1722816 is about 1312.5608557320. The cubic root of 1722816 is about 119.8798797996.

The spelling of 1722816 in words is "one million, seven hundred twenty-two thousand, eight hundred sixteen".