1720618 has 4 divisors (see below), whose sum is σ = 2580930. Its totient is φ = 860308.

The previous prime is 1720613. The next prime is 1720619. The reversal of 1720618 is 8160271.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1646089 + 74529 = 1283^2 + 273^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1720592 and 1720601.

It is not an unprimeable number, because it can be changed into a prime (1720613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430153 + ... + 430156.

2^1720618 is an apocalyptic number.

1720618 is a deficient number, since it is larger than the sum of its proper divisors (860312).

1720618 is an equidigital number, since it uses as much as digits as its factorization.

1720618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 860311.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 1720618 is about 1311.7232939915. The cubic root of 1720618 is about 119.8288764591.

Adding to 1720618 its reverse (8160271), we get a palindrome (9880889).

The spelling of 1720618 in words is "one million, seven hundred twenty thousand, six hundred eighteen".