1166555642501 has 2 divisors, whose sum is σ = 1166555642502. Its totient is φ = 1166555642500.

The previous prime is 1166555642437. The next prime is 1166555642519. The reversal of 1166555642501 is 1052465556611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1036678294276 + 129877348225 = 1018174^2 + 360385^2 .

It is a cyclic number.

It is not a de Polignac number, because 1166555642501 - 2⁶ = 1166555642437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1166555642521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 583277821250 + 583277821251.

It is an arithmetic number, because the mean of its divisors is an integer number (583277821251).

Almost surely, 2^{1166555642501} is an apocalyptic number.

It is an amenable number.

1166555642501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1166555642501 is an equidigital number, since it uses as much as digits as its factorization.

1166555642501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080000, while the sum is 47.

The spelling of 1166555642501 in words is "one trillion, one hundred sixty-six billion, five hundred fifty-five million, six hundred forty-two thousand, five hundred one".