1681601 has 4 divisors (see below), whose sum is σ = 1720752. Its totient is φ = 1642452.

The previous prime is 1681597. The next prime is 1681619. The reversal of 1681601 is 1061861.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1061861 = 113 ⋅9397.

It is a cyclic number.

It is not a de Polignac number, because 1681601 - 2² = 1681597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (1681621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19511 + ... + 19596.

It is an arithmetic number, because the mean of its divisors is an integer number (430188).

2^1681601 is an apocalyptic number.

It is an amenable number.

1681601 is a deficient number, since it is larger than the sum of its proper divisors (39151).

1681601 is an equidigital number, since it uses as much as digits as its factorization.

1681601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39150.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1681601 is about 1296.7655917705. The cubic root of 1681601 is about 118.9161898399.

The spelling of 1681601 in words is "one million, six hundred eighty-one thousand, six hundred one".