161161551105536 has 80 divisors (see below), whose sum is σ = 323693625697200. Its totient is φ = 80159084249088.

The previous prime is 161161551105509. The next prime is 161161551105571. The reversal of 161161551105536 is 635501155161161.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2899134830 + ... + 2899190418.

It is an arithmetic number, because the mean of its divisors is an integer number (4046170321215).

Almost surely, 2^{161161551105536} is an apocalyptic number.

161161551105536 is a gapful number since it is divisible by the number (16) 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 161161551105536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161846812848600).

161161551105536 is an abundant number, since it is smaller than the sum of its proper divisors (162532074591664).

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

161161551105536 is an equidigital number, since it uses as much as digits as its factorization.

161161551105536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85139 (or 85123 counting only the distinct ones).

The product of its (nonzero) digits is 405000, while the sum is 47.

The spelling of 161161551105536 in words is "one hundred sixty-one trillion, one hundred sixty-one billion, five hundred fifty-one million, one hundred five thousand, five hundred thirty-six".