161281816 has 32 divisors (see below), whose sum is σ = 317211840. Its totient is φ = 76785408.

The previous prime is 161281811. The next prime is 161281837. The reversal of 161281816 is 618182161.

It is a happy number.

161281816 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×161281816³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161281811) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8116 + ... + 19708.

It is an arithmetic number, because the mean of its divisors is an integer number (9912870).

Almost surely, 2^161281816 is an apocalyptic number.

It is an amenable number.

161281816 is a deficient number, since it is larger than the sum of its proper divisors (155930024).

161281816 is a wasteful number, since it uses less digits than its factorization.

161281816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11683 (or 11679 counting only the distinct ones).

The product of its digits is 4608, while the sum is 34.

The square root of 161281816 is about 12699.6777911882. The cubic root of 161281816 is about 544.3294122963.

The spelling of 161281816 in words is "one hundred sixty-one million, two hundred eighty-one thousand, eight hundred sixteen".