161131861037728 has 96 divisors (see below), whose sum is σ = 364026605217408. Its totient is φ = 68774676480000.

The previous prime is 161131861037723. The next prime is 161131861037737. The reversal of 161131861037728 is 827730168131161.

It is a super-3 number, since 3×161131861037728³ (a number of 44 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (161131861037723) 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, 599044708 + ... + 599313628.

It is an arithmetic number, because the mean of its divisors is an integer number (3791943804348).

Almost surely, 2^{161131861037728} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161131861037728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182013302608704).

161131861037728 is an abundant number, since it is smaller than the sum of its proper divisors (202894744179680).

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

161131861037728 is a wasteful number, since it uses less digits than its factorization.

161131861037728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279846 (or 279838 counting only the distinct ones).

The product of its (nonzero) digits is 2032128, while the sum is 55.

The spelling of 161131861037728 in words is "one hundred sixty-one trillion, one hundred thirty-one billion, eight hundred sixty-one million, thirty-seven thousand, seven hundred twenty-eight".