1720257 has 24 divisors (see below), whose sum is σ = 2885568. Its totient is φ = 892320.

The previous prime is 1720231. The next prime is 1720273. The reversal of 1720257 is 7520271.

It is not a de Polignac number, because 1720257 - 2¹⁰ = 1719233 is a prime.

1720257 is a lucky number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (1720217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2203 + ... + 2879.

It is an arithmetic number, because the mean of its divisors is an integer number (120232).

2^1720257 is an apocalyptic number.

It is an amenable number.

1720257 is a deficient number, since it is larger than the sum of its proper divisors (1165311).

1720257 is a wasteful number, since it uses less digits than its factorization.

1720257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 709 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 980, while the sum is 24.

The square root of 1720257 is about 1311.5856815321. The cubic root of 1720257 is about 119.8204955073.

The spelling of 1720257 in words is "one million, seven hundred twenty thousand, two hundred fifty-seven".