166011561511 has 2 divisors, whose sum is σ = 166011561512. Its totient is φ = 166011561510.

The previous prime is 166011561449. The next prime is 166011561539. The reversal of 166011561511 is 115165110661.

It is a strong prime.

It is an emirp because it is prime and its reverse (115165110661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166011561511 - 2²⁷ = 165877343783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166011561581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83005780755 + 83005780756.

It is an arithmetic number, because the mean of its divisors is an integer number (83005780756).

Almost surely, 2^166011561511 is an apocalyptic number.

166011561511 is a deficient number, since it is larger than the sum of its proper divisors (1).

166011561511 is an equidigital number, since it uses as much as digits as its factorization.

166011561511 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 34.

The spelling of 166011561511 in words is "one hundred sixty-six billion, eleven million, five hundred sixty-one thousand, five hundred eleven".