161823554920 has 64 divisors (see below), whose sum is σ = 371999589120. Its totient is φ = 63326694144.

The previous prime is 161823554911. The next prime is 161823554983. The reversal of 161823554920 is 29455328161.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5046859 + ... + 5078821.

It is an arithmetic number, because the mean of its divisors is an integer number (5812493580).

Almost surely, 2^161823554920 is an apocalyptic number.

161823554920 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 161823554920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (185999794560).

161823554920 is an abundant number, since it is smaller than the sum of its proper divisors (210176034200).

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

161823554920 is a wasteful number, since it uses less digits than its factorization.

161823554920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34714 (or 34710 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 46.

The spelling of 161823554920 in words is "one hundred sixty-one billion, eight hundred twenty-three million, five hundred fifty-four thousand, nine hundred twenty".