161000561660 has 96 divisors (see below), whose sum is σ = 354455402112. Its totient is φ = 61312204800.

The previous prime is 161000561653. The next prime is 161000561663. The reversal of 161000561660 is 66165000161.

161000561660 is a modest number, since divided by 561660 gives 161000 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161000561663) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 139635644 + ... + 139636796.

It is an arithmetic number, because the mean of its divisors is an integer number (3692243772).

Almost surely, 2^161000561660 is an apocalyptic number.

161000561660 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 161000561660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177227701056).

161000561660 is an abundant number, since it is smaller than the sum of its proper divisors (193454840452).

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

161000561660 is a wasteful number, since it uses less digits than its factorization.

161000561660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2343 (or 2341 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 32.

The spelling of 161000561660 in words is "one hundred sixty-one billion, five hundred sixty-one thousand, six hundred sixty".