161921088 has 126 divisors (see below), whose sum is σ = 539985966. Its totient is φ = 46255104.

The previous prime is 161921077. The next prime is 161921099. The reversal of 161921088 is 880129161.

It is an interprime number because it is at equal distance from previous prime (161921077) and next prime (161921099).

It can be written as a sum of positive squares in only one way, i.e., 88510464 + 73410624 = 9408^2 + 8568^2 .

It is a tau number, because it is divible by the number of its divisors (126).

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

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 17 ways as a sum of consecutive naturals, for example, 25356 + ... + 31092.

Almost surely, 2^161921088 is an apocalyptic number.

161921088 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 161921088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269992983).

161921088 is an abundant number, since it is smaller than the sum of its proper divisors (378064878).

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

161921088 is a wasteful number, since it uses less digits than its factorization.

161921088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5769 (or 5749 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 161921088 is about 12724.8217276314. The cubic root of 161921088 is about 545.0476495106.

The spelling of 161921088 in words is "one hundred sixty-one million, nine hundred twenty-one thousand, eighty-eight".