1605122201 has 4 divisors (see below), whose sum is σ = 1699541172. Its totient is φ = 1510703232.

The previous prime is 1605122191. The next prime is 1605122227. The reversal of 1605122201 is 1022215061.

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 1078465600 + 526656601 = 32840^2 + 22949^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1605122201 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1605122801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47209460 + ... + 47209493.

It is an arithmetic number, because the mean of its divisors is an integer number (424885293).

Almost surely, 2^1605122201 is an apocalyptic number.

It is an amenable number.

1605122201 is a deficient number, since it is larger than the sum of its proper divisors (94418971).

1605122201 is an equidigital number, since it uses as much as digits as its factorization.

1605122201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94418970.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1605122201 is about 40063.9763503325. The cubic root of 1605122201 is about 1170.8538829668.

Adding to 1605122201 its reverse (1022215061), we get a palindrome (2627337262).

The spelling of 1605122201 in words is "one billion, six hundred five million, one hundred twenty-two thousand, two hundred one".