6551666121 has 48 divisors (see below), whose sum is σ = 11817771392. Its totient is φ = 3141642240.

The previous prime is 6551666119. The next prime is 6551666129. The reversal of 6551666121 is 1216661556.

6551666121 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 6551666121 - 2¹ = 6551666119 is a prime.

It is a super-2 number, since 2×6551666121² = 85848657922118373282, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 6551666121.

It is not an unprimeable number, because it can be changed into a prime (6551666129) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 66136 + ... + 132201.

Almost surely, 2^6551666121 is an apocalyptic number.

It is an amenable number.

6551666121 is a deficient number, since it is larger than the sum of its proper divisors (5266105271).

6551666121 is a wasteful number, since it uses less digits than its factorization.

6551666121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198382 (or 198371 counting only the distinct ones).

The product of its digits is 64800, while the sum is 39.

The square root of 6551666121 is about 80942.3629566125. The cubic root of 6551666121 is about 1871.1872621959.

The spelling of 6551666121 in words is "six billion, five hundred fifty-one million, six hundred sixty-six thousand, one hundred twenty-one".