663541121 has 2 divisors, whose sum is σ = 663541122. Its totient is φ = 663541120.

The previous prime is 663541117. The next prime is 663541129. The reversal of 663541121 is 121145366.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 333610225 + 329930896 = 18265^2 + 18164^2 .

It is a cyclic number.

It is not a de Polignac number, because 663541121 - 2² = 663541117 is a prime.

It is not a weakly prime, because it can be changed into another prime (663541129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331770560 + 331770561.

It is an arithmetic number, because the mean of its divisors is an integer number (331770561).

Almost surely, 2^663541121 is an apocalyptic number.

It is an amenable number.

663541121 is a deficient number, since it is larger than the sum of its proper divisors (1).

663541121 is an equidigital number, since it uses as much as digits as its factorization.

663541121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 663541121 is about 25759.2919351445. The cubic root of 663541121 is about 872.2131178342.

Adding to 663541121 its reverse (121145366), we get a palindrome (784686487).

The spelling of 663541121 in words is "six hundred sixty-three million, five hundred forty-one thousand, one hundred twenty-one".