655501660121 has 16 divisors (see below), whose sum is σ = 818913328128. Its totient is φ = 509740198800.

The previous prime is 655501660097. The next prime is 655501660127. The reversal of 655501660121 is 121066105556.

It is a happy number.

It is not a de Polignac number, because 655501660121 - 2¹⁰ = 655501659097 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (655501660127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8631245 + ... + 8706858.

It is an arithmetic number, because the mean of its divisors is an integer number (51182083008).

Almost surely, 2^655501660121 is an apocalyptic number.

It is an amenable number.

655501660121 is a deficient number, since it is larger than the sum of its proper divisors (163411668007).

655501660121 is a wasteful number, since it uses less digits than its factorization.

655501660121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17338612.

The product of its (nonzero) digits is 54000, while the sum is 38.

Adding to 655501660121 its reverse (121066105556), we get a palindrome (776567765677).

The spelling of 655501660121 in words is "six hundred fifty-five billion, five hundred one million, six hundred sixty thousand, one hundred twenty-one".