20321663 has 8 divisors (see below), whose sum is σ = 21168000. Its totient is φ = 19485088.

The previous prime is 20321657. The next prime is 20321669. The reversal of 20321663 is 36612302.

It is an interprime number because it is at equal distance from previous prime (20321657) and next prime (20321669).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20321663 - 2⁶ = 20321599 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1970 + ... + 6672.

It is an arithmetic number, because the mean of its divisors is an integer number (2646000).

Almost surely, 2^20321663 is an apocalyptic number.

20321663 is a deficient number, since it is larger than the sum of its proper divisors (846337).

20321663 is a wasteful number, since it uses less digits than its factorization.

20321663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4881.

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 20321663 is about 4507.9555232943. The cubic root of 20321663 is about 272.8892420150.

Adding to 20321663 its reverse (36612302), we get a palindrome (56933965).

The spelling of 20321663 in words is "twenty million, three hundred twenty-one thousand, six hundred sixty-three".