161556365418 has 48 divisors (see below), whose sum is σ = 379378668384. Its totient is φ = 45727560480.

The previous prime is 161556365417. The next prime is 161556365459. The reversal of 161556365418 is 814563655161.

It is a super-2 number, since 2×161556365418² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161556365417) 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, 2536353 + ... + 2599268.

It is an arithmetic number, because the mean of its divisors is an integer number (7903722258).

Almost surely, 2^161556365418 is an apocalyptic number.

161556365418 is an abundant number, since it is smaller than the sum of its proper divisors (217822302966).

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

161556365418 is a wasteful number, since it uses less digits than its factorization.

161556365418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5135747 (or 5135740 counting only the distinct ones).

The product of its digits is 2592000, while the sum is 51.

The spelling of 161556365418 in words is "one hundred sixty-one billion, five hundred fifty-six million, three hundred sixty-five thousand, four hundred eighteen".