1721725 has 12 divisors (see below), whose sum is σ = 2171860. Its totient is φ = 1353600.

The previous prime is 1721719. The next prime is 1721729. The reversal of 1721725 is 5271271.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 695556 + 1026169 = 834^2 + 1013^2 .

It is not a de Polignac number, because 1721725 - 2³ = 1721717 is a prime.

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a self number, because there is not a number n which added to its sum of digits gives 1721725.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1721729) 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, 961 + ... + 2089.

2^1721725 is an apocalyptic number.

It is an amenable number.

1721725 is a deficient number, since it is larger than the sum of its proper divisors (450135).

1721725 is a wasteful number, since it uses less digits than its factorization.

1721725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1200 (or 1195 counting only the distinct ones).

The product of its digits is 980, while the sum is 25.

The square root of 1721725 is about 1312.1451901371. The cubic root of 1721725 is about 119.8545691906.

Adding to 1721725 its reverse (5271271), we get a palindrome (6992996).

The spelling of 1721725 in words is "one million, seven hundred twenty-one thousand, seven hundred twenty-five".