166536635661 has 128 divisors (see below), whose sum is σ = 287188070400. Its totient is φ = 94409038080.

The previous prime is 166536635659. The next prime is 166536635663.

166536635661 is a `hidden beast` number, since 16 + 6 + 5 + 3 + 6 + 63 + 566 + 1 = 666.

166536635661 is nontrivially palindromic in base 10.

166536635661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (166536635659) and next prime (166536635663).

It is not a de Polignac number, because 166536635661 - 2¹ = 166536635659 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 166536635598 and 166536635607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166536635663) 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 in 127 ways as a sum of consecutive naturals, for example, 83812110 + ... + 83814096.

It is an arithmetic number, because the mean of its divisors is an integer number (2243656800).

Almost surely, 2^166536635661 is an apocalyptic number.

166536635661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166536635661 is a deficient number, since it is larger than the sum of its proper divisors (120651434739).

166536635661 is a wasteful number, since it uses less digits than its factorization.

166536635661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2336 (or 2330 counting only the distinct ones).

The product of its digits is 10497600, while the sum is 54.

The spelling of 166536635661 in words is "one hundred sixty-six billion, five hundred thirty-six million, six hundred thirty-five thousand, six hundred sixty-one".