161224556544 has 640 divisors, whose sum is σ = 532878192000. Its totient is φ = 48349052928.

The previous prime is 161224556533. The next prime is 161224556551. The reversal of 161224556544 is 445655422161.

161224556544 is a `hidden beast` number, since 1 + 6 + 1 + 2 + 2 + 45 + 565 + 44 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 161224556544.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1159888827 + ... + 1159888965.

It is an arithmetic number, because the mean of its divisors is an integer number (832622175).

Almost surely, 2^161224556544 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 161224556544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266439096000).

161224556544 is an abundant number, since it is smaller than the sum of its proper divisors (371653635456).

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

161224556544 is an equidigital number, since it uses as much as digits as its factorization.

161224556544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223 (or 186 counting only the distinct ones).

The product of its digits is 1152000, while the sum is 45.

The spelling of 161224556544 in words is "one hundred sixty-one billion, two hundred twenty-four million, five hundred fifty-six thousand, five hundred forty-four".