11551666655531 has 2 divisors, whose sum is σ = 11551666655532. Its totient is φ = 11551666655530.

The previous prime is 11551666655513. The next prime is 11551666655597. The reversal of 11551666655531 is 13555666615511.

Together with previous prime (11551666655513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11551666655531 - 2¹⁴ = 11551666639147 is a prime.

It is a super-2 number, since 2×11551666655531² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (11551666654531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5775833327765 + 5775833327766.

It is an arithmetic number, because the mean of its divisors is an integer number (5775833327766).

Almost surely, 2^{11551666655531} is an apocalyptic number.

11551666655531 is a deficient number, since it is larger than the sum of its proper divisors (1).

11551666655531 is an equidigital number, since it uses as much as digits as its factorization.

11551666655531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12150000, while the sum is 56.

The spelling of 11551666655531 in words is "eleven trillion, five hundred fifty-one billion, six hundred sixty-six million, six hundred fifty-five thousand, five hundred thirty-one".