1720401 has 16 divisors (see below), whose sum is σ = 2395008. Its totient is φ = 1097600.

The previous prime is 1720399. The next prime is 1720421. The reversal of 1720401 is 1040271.

It is a cyclic number.

It is not a de Polignac number, because 1720401 - 2¹ = 1720399 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1720421) 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 15 ways as a sum of consecutive naturals, for example, 8635 + ... + 8831.

It is an arithmetic number, because the mean of its divisors is an integer number (149688).

2^1720401 is an apocalyptic number.

It is an amenable number.

1720401 is a deficient number, since it is larger than the sum of its proper divisors (674607).

1720401 is a wasteful number, since it uses less digits than its factorization.

1720401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312.

The product of its (nonzero) digits is 56, while the sum is 15.

The square root of 1720401 is about 1311.6405757676. The cubic root of 1720401 is about 119.8238387422.

Adding to 1720401 its reverse (1040271), we get a palindrome (2760672).

The spelling of 1720401 in words is "one million, seven hundred twenty thousand, four hundred one".