161121383280 has 960 divisors, whose sum is σ = 666077368320. Its totient is φ = 35979863040.

The previous prime is 161121383279. The next prime is 161121383341. The reversal of 161121383280 is 82383121161.

161121383280 is a `hidden beast` number, since 1 + 611 + 2 + 1 + 3 + 8 + 32 + 8 + 0 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 336370081 + ... + 336370559.

It is an arithmetic number, because the mean of its divisors is an integer number (693830592).

Almost surely, 2^161121383280 is an apocalyptic number.

161121383280 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 161121383280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (333038684160).

161121383280 is an abundant number, since it is smaller than the sum of its proper divisors (504955985040).

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

161121383280 is a wasteful number, since it uses less digits than its factorization.

161121383280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553 (or 513 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The spelling of 161121383280 in words is "one hundred sixty-one billion, one hundred twenty-one million, three hundred eighty-three thousand, two hundred eighty".