663601121 has 4 divisors (see below), whose sum is σ = 666936000. Its totient is φ = 660266244.

The previous prime is 663601091. The next prime is 663601123. The reversal of 663601121 is 121106366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 121106366 = 2 ⋅60553183.

It is a cyclic number.

It is not a de Polignac number, because 663601121 - 2¹⁴ = 663584737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (663601123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1667141 + ... + 1667538.

It is an arithmetic number, because the mean of its divisors is an integer number (166734000).

Almost surely, 2^663601121 is an apocalyptic number.

It is an amenable number.

663601121 is a deficient number, since it is larger than the sum of its proper divisors (3334879).

663601121 is a wasteful number, since it uses less digits than its factorization.

663601121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3334878.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 663601121 is about 25760.4565371035. The cubic root of 663601121 is about 872.2394066896.

Adding to 663601121 its reverse (121106366), we get a palindrome (784707487).

The spelling of 663601121 in words is "six hundred sixty-three million, six hundred one thousand, one hundred twenty-one".