12500191584721 has 3 divisors (see below), whose sum is σ = 12500195120283. Its totient is φ = 12500188049160.

The previous prime is 12500191584691. The next prime is 12500191584733. The reversal of 12500191584721 is 12748519100521.

The square root of 12500191584721 is 3535561.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 5946106321 + 12494245478400 = 77111^2 + 3534720^2 .

It is not a de Polignac number, because 12500191584721 - 2¹⁷ = 12500191453649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12500191524721) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1767781 + ... + 5303341.

It is an arithmetic number, because the mean of its divisors is an integer number (4166731706761).

Almost surely, 2^{12500191584721} is an apocalyptic number.

12500191584721 is the 3535561-st square number.

12500191584721 is the 1767781-st centered octagonal number.

It is an amenable number.

12500191584721 is a deficient number, since it is larger than the sum of its proper divisors (3535562).

12500191584721 is an frugal number, since it uses more digits than its factorization.

12500191584721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7071122 (or 3535561 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 46.

The spelling of 12500191584721 in words is "twelve trillion, five hundred billion, one hundred ninety-one million, five hundred eighty-four thousand, seven hundred twenty-one".