1720667 has 8 divisors (see below), whose sum is σ = 1871856. Its totient is φ = 1572192.

The previous prime is 1720643. The next prime is 1720669. The reversal of 1720667 is 7660271.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1720667 - 2⁶ = 1720603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1720669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 773 + ... + 2009.

It is an arithmetic number, because the mean of its divisors is an integer number (233982).

2^1720667 is an apocalyptic number.

1720667 is a deficient number, since it is larger than the sum of its proper divisors (151189).

1720667 is a wasteful number, since it uses less digits than its factorization.

1720667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1357.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 1720667 is about 1311.7419715783. The cubic root of 1720667 is about 119.8300139495.

The spelling of 1720667 in words is "one million, seven hundred twenty thousand, six hundred sixty-seven".