1722729 has 12 divisors (see below), whose sum is σ = 2441264. Its totient is φ = 1080384.

The previous prime is 1722719. The next prime is 1722731. The reversal of 1722729 is 9272271.

It is a happy number.

1722729 is nontrivially palindromic in base 9.

It is not a de Polignac number, because 1722729 - 2⁴ = 1722713 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1722696 and 1722705.

It is not an unprimeable number, because it can be changed into a prime (1722719) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 127 + ... + 1860.

2^1722729 is an apocalyptic number.

It is an amenable number.

1722729 is a deficient number, since it is larger than the sum of its proper divisors (718535).

1722729 is a wasteful number, since it uses less digits than its factorization.

1722729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2024 (or 2007 counting only the distinct ones).

The product of its digits is 3528, while the sum is 30.

The square root of 1722729 is about 1312.5277139931. The cubic root of 1722729 is about 119.8778618389.

The spelling of 1722729 in words is "one million, seven hundred twenty-two thousand, seven hundred twenty-nine".