161641544800 has 144 divisors (see below), whose sum is σ = 412145964720. Its totient is φ = 61842216960.

The previous prime is 161641544789. The next prime is 161641544803. The reversal of 161641544800 is 8445146161.

It is a super-2 number, since 2×161641544800² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161641544803) 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, 1700122 + ... + 1792678.

It is an arithmetic number, because the mean of its divisors is an integer number (2862124755).

Almost surely, 2^161641544800 is an apocalyptic number.

161641544800 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 161641544800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (206072982360).

161641544800 is an abundant number, since it is smaller than the sum of its proper divisors (250504419920).

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

161641544800 is a wasteful number, since it uses less digits than its factorization.

161641544800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92673 (or 92660 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 40.

The spelling of 161641544800 in words is "one hundred sixty-one billion, six hundred forty-one million, five hundred forty-four thousand, eight hundred".