161591808 has 240 divisors, whose sum is σ = 531796320. Its totient is φ = 43352064.

The previous prime is 161591777. The next prime is 161591849. The reversal of 161591808 is 808195161.

It is a super-2 number, since 2×161591808² = 52223824825417728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1429960 + ... + 1430072.

It is an arithmetic number, because the mean of its divisors is an integer number (2215818).

Almost surely, 2^161591808 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 161591808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265898160).

161591808 is an abundant number, since it is smaller than the sum of its proper divisors (370204512).

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

161591808 is a wasteful number, since it uses less digits than its factorization.

161591808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 39.

The square root of 161591808 is about 12711.8766513839. The cubic root of 161591808 is about 544.6779322040.

The spelling of 161591808 in words is "one hundred sixty-one million, five hundred ninety-one thousand, eight hundred eight".