1663710321 has 64 divisors (see below), whose sum is σ = 2912716800. Its totient is φ = 819680256.

The previous prime is 1663710241. The next prime is 1663710329. The reversal of 1663710321 is 1230173661.

It is not a de Polignac number, because 1663710321 - 2¹⁰ = 1663709297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1663710329) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 643810 + ... + 646388.

It is an arithmetic number, because the mean of its divisors is an integer number (45511200).

Almost surely, 2^1663710321 is an apocalyptic number.

It is an amenable number.

1663710321 is a deficient number, since it is larger than the sum of its proper divisors (1249006479).

1663710321 is a wasteful number, since it uses less digits than its factorization.

1663710321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2758.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 1663710321 is about 40788.6052838290. The cubic root of 1663710321 is about 1184.9296595182.

Adding to 1663710321 its reverse (1230173661), we get a palindrome (2893883982).

The spelling of 1663710321 in words is "one billion, six hundred sixty-three million, seven hundred ten thousand, three hundred twenty-one".