20663121 has 8 divisors (see below), whose sum is σ = 27656640. Its totient is φ = 13722512.

The previous prime is 20663107. The next prime is 20663147. The reversal of 20663121 is 12136602.

It is a happy number.

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 20663121 - 2¹⁴ = 20646737 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20663191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12306 + ... + 13883.

It is an arithmetic number, because the mean of its divisors is an integer number (3457080).

Almost surely, 2^20663121 is an apocalyptic number.

It is an amenable number.

20663121 is a deficient number, since it is larger than the sum of its proper divisors (6993519).

20663121 is a wasteful number, since it uses less digits than its factorization.

20663121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26455.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 20663121 is about 4545.6705775936. The cubic root of 20663121 is about 274.4091822683.

Adding to 20663121 its reverse (12136602), we get a palindrome (32799723).

The spelling of 20663121 in words is "twenty million, six hundred sixty-three thousand, one hundred twenty-one".