6693728121 has 72 divisors (see below), whose sum is σ = 10655012160. Its totient is φ = 4045976064.

The previous prime is 6693728117. The next prime is 6693728147. The reversal of 6693728121 is 1218273966.

It is not a de Polignac number, because 6693728121 - 2² = 6693728117 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6693728191) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8132916 + ... + 8133738.

It is an arithmetic number, because the mean of its divisors is an integer number (147986280).

Almost surely, 2^6693728121 is an apocalyptic number.

It is an amenable number.

6693728121 is a deficient number, since it is larger than the sum of its proper divisors (3961284039).

6693728121 is a wasteful number, since it uses less digits than its factorization.

6693728121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 975 (or 955 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 6693728121 is about 81815.2071500158. The cubic root of 6693728121 is about 1884.6152001553.

The spelling of 6693728121 in words is "six billion, six hundred ninety-three million, seven hundred twenty-eight thousand, one hundred twenty-one".