1617221 has 4 divisors (see below), whose sum is σ = 1621152. Its totient is φ = 1613292.

The previous prime is 1617211. The next prime is 1617247. The reversal of 1617221 is 1227161.

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: 1227161 = 13 ⋅94397.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1617221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1617193 and 1617202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1617211) 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, 1265 + ... + 2198.

It is an arithmetic number, because the mean of its divisors is an integer number (405288).

2^1617221 is an apocalyptic number.

It is an amenable number.

1617221 is a deficient number, since it is larger than the sum of its proper divisors (3931).

1617221 is an equidigital number, since it uses as much as digits as its factorization.

1617221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3930.

The product of its digits is 168, while the sum is 20.

The square root of 1617221 is about 1271.7000432492. The cubic root of 1617221 is about 117.3788339013.

The spelling of 1617221 in words is "one million, six hundred seventeen thousand, two hundred twenty-one".