161281278 has 24 divisors (see below), whose sum is σ = 369998928. Its totient is φ = 50597952.

The previous prime is 161281277. The next prime is 161281301. The reversal of 161281278 is 872182161.

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (161281277) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 263226 + ... + 263837.

It is an arithmetic number, because the mean of its divisors is an integer number (15416622).

Almost surely, 2^161281278 is an apocalyptic number.

161281278 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161281278 is an abundant number, since it is smaller than the sum of its proper divisors (208717650).

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

161281278 is a wasteful number, since it uses less digits than its factorization.

161281278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527088 (or 527085 counting only the distinct ones).

The product of its digits is 10752, while the sum is 36.

The square root of 161281278 is about 12699.6566095308. The cubic root of 161281278 is about 544.3288070419.

The spelling of 161281278 in words is "one hundred sixty-one million, two hundred eighty-one thousand, two hundred seventy-eight".