1613221 has 4 divisors (see below), whose sum is σ = 1619244. Its totient is φ = 1607200.

The previous prime is 1613201. The next prime is 1613279. The reversal of 1613221 is 1223161.

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 950625 + 662596 = 975^2 + 814^2 .

It is a cyclic number.

It is not a de Polignac number, because 1613221 - 2⁷ = 1613093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1613195 and 1613204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1613201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2590 + ... + 3151.

It is an arithmetic number, because the mean of its divisors is an integer number (404811).

2^1613221 is an apocalyptic number.

It is an amenable number.

1613221 is a deficient number, since it is larger than the sum of its proper divisors (6023).

1613221 is an equidigital number, since it uses as much as digits as its factorization.

1613221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6022.

The product of its digits is 72, while the sum is 16.

The square root of 1613221 is about 1270.1263716654. The cubic root of 1613221 is about 117.2819799020.

Adding to 1613221 its reverse (1223161), we get a palindrome (2836382).

The spelling of 1613221 in words is "one million, six hundred thirteen thousand, two hundred twenty-one".