161390880 has 288 divisors, whose sum is σ = 653837184. Its totient is φ = 36827136.

The previous prime is 161390869. The next prime is 161390893. The reversal of 161390880 is 88093161.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×161390880² = 52094032294348800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 271864 + ... + 272456.

It is an arithmetic number, because the mean of its divisors is an integer number (2270268).

Almost surely, 2^161390880 is an apocalyptic number.

161390880 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 161390880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326918592).

161390880 is an abundant number, since it is smaller than the sum of its proper divisors (492446304).

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

161390880 is an equidigital number, since it uses as much as digits as its factorization.

161390880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630 (or 610 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 161390880 is about 12703.9710327126. The cubic root of 161390880 is about 544.4520823893.

The spelling of 161390880 in words is "one hundred sixty-one million, three hundred ninety thousand, eight hundred eighty".