1661201 has 4 divisors (see below), whose sum is σ = 1672500. Its totient is φ = 1649904.

The previous prime is 1661173. The next prime is 1661237. The reversal of 1661201 is 1021661.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 336400 + 1324801 = 580^2 + 1151^2 .

It is a cyclic number.

It is not a de Polignac number, because 1661201 - 2⁶ = 1661137 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1661201.

It is not an unprimeable number, because it can be changed into a prime (1661251) 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, 5426 + ... + 5723.

It is an arithmetic number, because the mean of its divisors is an integer number (418125).

2^1661201 is an apocalyptic number.

It is an amenable number.

1661201 is a deficient number, since it is larger than the sum of its proper divisors (11299).

1661201 is a wasteful number, since it uses less digits than its factorization.

1661201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11298.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 1661201 is about 1288.8758667925. The cubic root of 1661201 is about 118.4333629273.

Adding to 1661201 its reverse (1021661), we get a palindrome (2682862).

The spelling of 1661201 in words is "one million, six hundred sixty-one thousand, two hundred one".