166034635665021 has 24 divisors (see below), whose sum is σ = 264975991450560. Its totient is φ = 99649090797696.

The previous prime is 166034635665013. The next prime is 166034635665071. The reversal of 166034635665021 is 120566536430661.

166034635665021 is a `hidden beast` number, since 1 + 6 + 6 + 0 + 3 + 4 + 6 + 3 + 566 + 50 + 21 = 666.

It is not a de Polignac number, because 166034635665021 - 2³ = 166034635665013 is a prime.

It is a super-5 number, since 5×166034635665021⁵ (a number of 72 digits) contains 55555 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166034635665011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23591163811 + ... + 23591170848.

It is an arithmetic number, because the mean of its divisors is an integer number (11040666310440).

Almost surely, 2^{166034635665021} is an apocalyptic number.

It is an amenable number.

166034635665021 is a deficient number, since it is larger than the sum of its proper divisors (98941355785539).

166034635665021 is a wasteful number, since it uses less digits than its factorization.

166034635665021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47182334705 (or 47182334702 counting only the distinct ones).

The product of its (nonzero) digits is 13996800, while the sum is 54.

The spelling of 166034635665021 in words is "one hundred sixty-six trillion, thirty-four billion, six hundred thirty-five million, six hundred sixty-five thousand, twenty-one".