161606565666601 has 16 divisors (see below), whose sum is σ = 184001524253568. Its totient is φ = 140498176896000.

The previous prime is 161606565666569. The next prime is 161606565666619. The reversal of 161606565666601 is 106666565606161.

It is not a de Polignac number, because 161606565666601 - 2⁵ = 161606565666569 is a prime.

It is a super-2 number, since 2×161606565666601² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161606565666601.

It is not an unprimeable number, because it can be changed into a prime (161606565666631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65309106 + ... + 67738411.

It is an arithmetic number, because the mean of its divisors is an integer number (11500095265848).

Almost surely, 2^{161606565666601} is an apocalyptic number.

161606565666601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161606565666601 is a deficient number, since it is larger than the sum of its proper divisors (22394958586967).

161606565666601 is a wasteful number, since it uses less digits than its factorization.

161606565666601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133052352.

The product of its (nonzero) digits is 41990400, while the sum is 61.

The spelling of 161606565666601 in words is "one hundred sixty-one trillion, six hundred six billion, five hundred sixty-five million, six hundred sixty-six thousand, six hundred one".