15666504086243 has 4 divisors (see below), whose sum is σ = 15666515451000. Its totient is φ = 15666492721488.

The previous prime is 15666504086239. The next prime is 15666504086269. The reversal of 15666504086243 is 34268040566651.

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 is a cyclic number.

It is not a de Polignac number, because 15666504086243 - 2² = 15666504086239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15666504086203) 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, 3274493 + ... + 6485006.

It is an arithmetic number, because the mean of its divisors is an integer number (3916628862750).

Almost surely, 2^{15666504086243} is an apocalyptic number.

15666504086243 is a deficient number, since it is larger than the sum of its proper divisors (11364757).

15666504086243 is an equidigital number, since it uses as much as digits as its factorization.

15666504086243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11364756.

The product of its (nonzero) digits is 24883200, while the sum is 56.

The spelling of 15666504086243 in words is "fifteen trillion, six hundred sixty-six billion, five hundred four million, eighty-six thousand, two hundred forty-three".