660136121 has 4 divisors (see below), whose sum is σ = 676237044. Its totient is φ = 644035200.

The previous prime is 660136109. The next prime is 660136123. The reversal of 660136121 is 121631066.

660136121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 184416400 + 475719721 = 13580^2 + 21811^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660136121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660136123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8050400 + ... + 8050481.

It is an arithmetic number, because the mean of its divisors is an integer number (169059261).

Almost surely, 2^660136121 is an apocalyptic number.

It is an amenable number.

660136121 is a deficient number, since it is larger than the sum of its proper divisors (16100923).

660136121 is a wasteful number, since it uses less digits than its factorization.

660136121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16100922.

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

The square root of 660136121 is about 25693.1142721158. The cubic root of 660136121 is about 870.7186210343.

Adding to 660136121 its reverse (121631066), we get a palindrome (781767187).

The spelling of 660136121 in words is "six hundred sixty million, one hundred thirty-six thousand, one hundred twenty-one".