16706071661021 has 4 divisors (see below), whose sum is σ = 16722434122044. Its totient is φ = 16689709200000.

The previous prime is 16706071660997. The next prime is 16706071661047. The reversal of 16706071661021 is 12016617060761.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12470687080996 + 4235384580025 = 3531386^2 + 2058005^2 .

It is a cyclic number.

It is not a de Polignac number, because 16706071661021 - 2²² = 16706067466717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16706071660021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8181228980 + ... + 8181231021.

It is an arithmetic number, because the mean of its divisors is an integer number (4180608530511).

Almost surely, 2^{16706071661021} is an apocalyptic number.

It is an amenable number.

16706071661021 is a deficient number, since it is larger than the sum of its proper divisors (16362461023).

16706071661021 is a wasteful number, since it uses less digits than its factorization.

16706071661021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16362461022.

The product of its (nonzero) digits is 127008, while the sum is 44.

The spelling of 16706071661021 in words is "sixteen trillion, seven hundred six billion, seventy-one million, six hundred sixty-one thousand, twenty-one".