1663121 has 4 divisors (see below), whose sum is σ = 1720500. Its totient is φ = 1605744.

The previous prime is 1663117. The next prime is 1663133. The reversal of 1663121 is 1213661.

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 923521 + 739600 = 961^2 + 860^2 .

It is a cyclic number.

It is not a de Polignac number, because 1663121 - 2² = 1663117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1663093 and 1663102.

It is not an unprimeable number, because it can be changed into a prime (1663721) 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, 28646 + ... + 28703.

It is an arithmetic number, because the mean of its divisors is an integer number (430125).

2^1663121 is an apocalyptic number.

It is an amenable number.

1663121 is a deficient number, since it is larger than the sum of its proper divisors (57379).

1663121 is an equidigital number, since it uses as much as digits as its factorization.

1663121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57378.

The product of its digits is 216, while the sum is 20.

The square root of 1663121 is about 1289.6204868100. The cubic root of 1663121 is about 118.4789734038.

Adding to 1663121 its reverse (1213661), we get a palindrome (2876782).

The spelling of 1663121 in words is "one million, six hundred sixty-three thousand, one hundred twenty-one".