12651066221 has 4 divisors (see below), whose sum is σ = 12824368572. Its totient is φ = 12477763872.

The previous prime is 12651066217. The next prime is 12651066247. The reversal of 12651066221 is 12266015621.

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 4074268900 + 8576797321 = 63830^2 + 92611^2 .

It is a cyclic number.

It is not a de Polignac number, because 12651066221 - 2² = 12651066217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12651066251) 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, 86651066 + ... + 86651211.

It is an arithmetic number, because the mean of its divisors is an integer number (3206092143).

Almost surely, 2^12651066221 is an apocalyptic number.

It is an amenable number.

12651066221 is a deficient number, since it is larger than the sum of its proper divisors (173302351).

12651066221 is an equidigital number, since it uses as much as digits as its factorization.

12651066221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173302350.

The product of its (nonzero) digits is 8640, while the sum is 32.

The spelling of 12651066221 in words is "twelve billion, six hundred fifty-one million, sixty-six thousand, two hundred twenty-one".