12345555566691 has 12 divisors (see below), whose sum is σ = 18124804712560. Its totient is φ = 8095446272880.

The previous prime is 12345555566657. The next prime is 12345555566731. The reversal of 12345555566691 is 19666555554321.

It is not a de Polignac number, because 12345555566691 - 2⁶ = 12345555566627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12345555566611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11243674831 + ... + 11243675928.

Almost surely, 2^{12345555566691} is an apocalyptic number.

12345555566691 is a deficient number, since it is larger than the sum of its proper divisors (5779249145869).

12345555566691 is a wasteful number, since it uses less digits than its factorization.

12345555566691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22487350826 (or 22487350823 counting only the distinct ones).

The product of its digits is 145800000, while the sum is 63.

The spelling of 12345555566691 in words is "twelve trillion, three hundred forty-five billion, five hundred fifty-five million, five hundred sixty-six thousand, six hundred ninety-one".