1720642 has 16 divisors (see below), whose sum is σ = 3218112. Its totient is φ = 670320.

The previous prime is 1720639. The next prime is 1720643. The reversal of 1720642 is 2460271.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a d-powerful number, because it can be written as 1 + 7² + 2¹³ + 0 + 6⁸ + 4² + 2¹⁵ .

It is not an unprimeable number, because it can be changed into a prime (1720643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5433 + ... + 5740.

It is an arithmetic number, because the mean of its divisors is an integer number (201132).

2^1720642 is an apocalyptic number.

1720642 is a deficient number, since it is larger than the sum of its proper divisors (1497470).

1720642 is a wasteful number, since it uses less digits than its factorization.

1720642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11193.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 1720642 is about 1311.7324422305. The cubic root of 1720642 is about 119.8294336000.

The spelling of 1720642 in words is "one million, seven hundred twenty thousand, six hundred forty-two".