1663135221 has 32 divisors (see below), whose sum is σ = 2529377280. Its totient is φ = 962192000.

The previous prime is 1663135207. The next prime is 1663135261. The reversal of 1663135221 is 1225313661.

It is not a de Polignac number, because 1663135221 - 2⁶ = 1663135157 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663135261) 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 31 ways as a sum of consecutive naturals, for example, 429946 + ... + 433796.

It is an arithmetic number, because the mean of its divisors is an integer number (79043040).

Almost surely, 2^1663135221 is an apocalyptic number.

1663135221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1663135221 is a deficient number, since it is larger than the sum of its proper divisors (866242059).

1663135221 is a wasteful number, since it uses less digits than its factorization.

1663135221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4457.

The product of its digits is 6480, while the sum is 30.

The square root of 1663135221 is about 40781.5549115038. The cubic root of 1663135221 is about 1184.7931109910.

Adding to 1663135221 its reverse (1225313661), we get a palindrome (2888448882).

The spelling of 1663135221 in words is "one billion, six hundred sixty-three million, one hundred thirty-five thousand, two hundred twenty-one".