166660556149 has 2 divisors, whose sum is σ = 166660556150. Its totient is φ = 166660556148.

The previous prime is 166660556131. The next prime is 166660556177. The reversal of 166660556149 is 941655066661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157216215025 + 9444341124 = 396505^2 + 97182^2 .

It is a cyclic number.

It is not a de Polignac number, because 166660556149 - 2¹³ = 166660547957 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166660556149.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166660556189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83330278074 + 83330278075.

It is an arithmetic number, because the mean of its divisors is an integer number (83330278075).

Almost surely, 2^166660556149 is an apocalyptic number.

It is an amenable number.

166660556149 is a deficient number, since it is larger than the sum of its proper divisors (1).

166660556149 is an equidigital number, since it uses as much as digits as its factorization.

166660556149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6998400, while the sum is 55.

The spelling of 166660556149 in words is "one hundred sixty-six billion, six hundred sixty million, five hundred fifty-six thousand, one hundred forty-nine".