161644173600 has 1296 divisors, whose sum is σ = 695195379648. Its totient is φ = 31936020480.

The previous prime is 161644173569. The next prime is 161644173619. The reversal of 161644173600 is 6371446161.

It is a super-2 number, since 2×161644173600² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 820528702 + ... + 820528898.

It is an arithmetic number, because the mean of its divisors is an integer number (536416188).

Almost surely, 2^161644173600 is an apocalyptic number.

161644173600 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 161644173600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (347597689824).

161644173600 is an abundant number, since it is smaller than the sum of its proper divisors (533551206048).

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

161644173600 is a wasteful number, since it uses less digits than its factorization.

161644173600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

It can be divided in two parts, 1616441 and 73600, that added together give a triangular number (1690041 = T₁₈₃₈).

The spelling of 161644173600 in words is "one hundred sixty-one billion, six hundred forty-four million, one hundred seventy-three thousand, six hundred".