12501065646666 has 20 divisors (see below), whose sum is σ = 28011647097522. Its totient is φ = 4167021882168.

The previous prime is 12501065646661. The next prime is 12501065646691. The reversal of 12501065646666 is 66664656010521.

It can be written as a sum of positive squares in only one way, i.e., 12262105989441 + 238959657225 = 3501729^2 + 488835^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (12501065646661) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 38583535785 + ... + 38583536108.

Almost surely, 2^{12501065646666} is an apocalyptic number.

12501065646666 is an abundant number, since it is smaller than the sum of its proper divisors (15510581450856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12501065646666 is an equidigital number, since it uses as much as digits as its factorization.

12501065646666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77167071907 (or 77167071898 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 54.

The spelling of 12501065646666 in words is "twelve trillion, five hundred one billion, sixty-five million, six hundred forty-six thousand, six hundred sixty-six".