161666106556100 has 72 divisors (see below), whose sum is σ = 352924881236928. Its totient is φ = 64277626787200.

The previous prime is 161666106556043. The next prime is 161666106556103. The reversal of 161666106556100 is 1655601666161.

It is a super-2 number, since 2×161666106556100² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is not an unprimeable number, because it can be changed into a prime (161666106556103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 858502955 + ... + 858691245.

It is an arithmetic number, because the mean of its divisors is an integer number (4901734461624).

Almost surely, 2^{161666106556100} is an apocalyptic number.

161666106556100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161666106556100 is an abundant number, since it is smaller than the sum of its proper divisors (191258774680828).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161666106556100 is a wasteful number, since it uses less digits than its factorization.

161666106556100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239885 (or 239878 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 50.

The spelling of 161666106556100 in words is "one hundred sixty-one trillion, six hundred sixty-six billion, one hundred six million, five hundred fifty-six thousand, one hundred".