161998831008 has 432 divisors, whose sum is σ = 570815822304. Its totient is φ = 45030504960.

The previous prime is 161998830943. The next prime is 161998831019. The reversal of 161998831008 is 800138899161.

161998831008 is a `hidden beast` number, since 1 + 619 + 9 + 8 + 8 + 3 + 10 + 0 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 14092143 + ... + 14103633.

It is an arithmetic number, because the mean of its divisors is an integer number (1321332922).

Almost surely, 2^161998831008 is an apocalyptic number.

161998831008 is a gapful number since it is divisible by the number (18) 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 161998831008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (285407911152).

161998831008 is an abundant number, since it is smaller than the sum of its proper divisors (408816991296).

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

161998831008 is a wasteful number, since it uses less digits than its factorization.

161998831008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11567 (or 11540 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 54.

The spelling of 161998831008 in words is "one hundred sixty-one billion, nine hundred ninety-eight million, eight hundred thirty-one thousand, eight".