166661011556 has 12 divisors (see below), whose sum is σ = 314091906492. Its totient is φ = 76920466848.

The previous prime is 166661011423. The next prime is 166661011669. The reversal of 166661011556 is 655110166661.

It can be written as a sum of positive squares in 2 ways, for example, as 53145925156 + 113515086400 = 230534^2 + 336920^2 .

It is a super-2 number, since 2×166661011556² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1602509675 + ... + 1602509778.

It is an arithmetic number, because the mean of its divisors is an integer number (26174325541).

Almost surely, 2^166661011556 is an apocalyptic number.

It is an amenable number.

166661011556 is a deficient number, since it is larger than the sum of its proper divisors (147430894936).

166661011556 is a wasteful number, since it uses less digits than its factorization.

166661011556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3205019470 (or 3205019468 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 44.

The spelling of 166661011556 in words is "one hundred sixty-six billion, six hundred sixty-one million, eleven thousand, five hundred fifty-six".