1720005 has 16 divisors (see below), whose sum is σ = 3145344. Its totient is φ = 786240.

The previous prime is 1720003. The next prime is 1720031. The reversal of 1720005 is 5000271.

It is a happy number.

It is not a de Polignac number, because 1720005 - 2¹ = 1720003 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8086 + ... + 8295.

It is an arithmetic number, because the mean of its divisors is an integer number (196584).

2^1720005 is an apocalyptic number.

1720005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1720005 is a deficient number, since it is larger than the sum of its proper divisors (1425339).

1720005 is a wasteful number, since it uses less digits than its factorization.

1720005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16396.

The product of its (nonzero) digits is 70, while the sum is 15.

The square root of 1720005 is about 1311.4896110911. The cubic root of 1720005 is about 119.8146443971.

Adding to 1720005 its reverse (5000271), we get a palindrome (6720276).

The spelling of 1720005 in words is "one million, seven hundred twenty thousand, five".