161091378 has 48 divisors (see below), whose sum is σ = 408635136. Its totient is φ = 44902080.

The previous prime is 161091341. The next prime is 161091391. The reversal of 161091378 is 873190161.

161091378 is a `hidden beast` number, since 1 + 610 + 9 + 1 + 37 + 8 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10426 + ... + 20757.

It is an arithmetic number, because the mean of its divisors is an integer number (8513232).

Almost surely, 2^161091378 is an apocalyptic number.

161091378 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161091378 is an abundant number, since it is smaller than the sum of its proper divisors (247543758).

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

161091378 is a wasteful number, since it uses less digits than its factorization.

161091378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31239 (or 31236 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 161091378 is about 12692.1778273077. The cubic root of 161091378 is about 544.1150838737.

The spelling of 161091378 in words is "one hundred sixty-one million, ninety-one thousand, three hundred seventy-eight".