161661611616066 has 48 divisors (see below), whose sum is σ = 352789687111680. Its totient is φ = 53499077765280.

The previous prime is 161661611615983. The next prime is 161661611616073. The reversal of 161661611616066 is 660616116166161.

161661611616066 is a `hidden beast` number, since 1 + 6 + 1 + 6 + 6 + 1 + 6 + 11 + 616 + 0 + 6 + 6 = 666.

161661611616066 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×161661611616066² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 443905471 + ... + 444269501.

It is an arithmetic number, because the mean of its divisors is an integer number (7349785148160).

Almost surely, 2^{161661611616066} is an apocalyptic number.

161661611616066 is an abundant number, since it is smaller than the sum of its proper divisors (191128075495614).

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

161661611616066 is a wasteful number, since it uses less digits than its factorization.

161661611616066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541671 (or 541668 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The spelling of 161661611616066 in words is "one hundred sixty-one trillion, six hundred sixty-one billion, six hundred eleven million, six hundred sixteen thousand, sixty-six".