161605056665520 has 480 divisors, whose sum is σ = 604907800922880. Its totient is φ = 38390079651840.

The previous prime is 161605056665461. The next prime is 161605056665527. The reversal of 161605056665520 is 25566650506161.

It is a super-2 number, since 2×161605056665520² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161605056665527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 586444089 + ... + 586719591.

It is an arithmetic number, because the mean of its divisors is an integer number (1260224585256).

Almost surely, 2^{161605056665520} is an apocalyptic number.

161605056665520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161605056665520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (302453900461440).

161605056665520 is an abundant number, since it is smaller than the sum of its proper divisors (443302744257360).

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

161605056665520 is a wasteful number, since it uses less digits than its factorization.

161605056665520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277725 (or 277716 counting only the distinct ones).

The product of its (nonzero) digits is 9720000, while the sum is 54.

The spelling of 161605056665520 in words is "one hundred sixty-one trillion, six hundred five billion, fifty-six million, six hundred sixty-five thousand, five hundred twenty".