161205678 has 12 divisors (see below), whose sum is σ = 349279008. Its totient is φ = 53735220.

The previous prime is 161205677. The next prime is 161205697. The reversal of 161205678 is 876502161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161205677) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 4477918 + ... + 4477953.

It is an arithmetic number, because the mean of its divisors is an integer number (29106584).

Almost surely, 2^161205678 is an apocalyptic number.

161205678 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161205678 is an abundant number, since it is smaller than the sum of its proper divisors (188073330).

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

161205678 is a wasteful number, since it uses less digits than its factorization.

161205678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8955879 (or 8955876 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 161205678 is about 12696.6798022160. The cubic root of 161205678 is about 544.2437430473.

The spelling of 161205678 in words is "one hundred sixty-one million, two hundred five thousand, six hundred seventy-eight".