166666666556 has 24 divisors (see below), whose sum is σ = 314207177424. Its totient is φ = 76897457280.

The previous prime is 166666666549. The next prime is 166666666559. The reversal of 166666666556 is 655666666661.

It is a super-2 number, since 2×166666666556² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 166666666492 and 166666666501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166666666559) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 375665 + ... + 688808.

It is an arithmetic number, because the mean of its divisors is an integer number (13091965726).

Almost surely, 2^166666666556 is an apocalyptic number.

It is an amenable number.

166666666556 is a deficient number, since it is larger than the sum of its proper divisors (147540510868).

166666666556 is a wasteful number, since it uses less digits than its factorization.

166666666556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1067501 (or 1067499 counting only the distinct ones).

The product of its digits is 251942400, while the sum is 65.

It can be divided in two parts, 16666666655 and 6, that added together give a palindrome (16666666661).

The spelling of 166666666556 in words is "one hundred sixty-six billion, six hundred sixty-six million, six hundred sixty-six thousand, five hundred fifty-six".