1816181406 has 64 divisors (see below), whose sum is σ = 4387219200. Its totient is φ = 553579488.

The previous prime is 1816181377. The next prime is 1816181441. The reversal of 1816181406 is 6041816181.

1816181406 is a `hidden beast` number, since 18 + 161 + 81 + 406 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63025 + ... + 87203.

It is an arithmetic number, because the mean of its divisors is an integer number (68550300).

Almost surely, 2^1816181406 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1816181406, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2193609600).

1816181406 is an abundant number, since it is smaller than the sum of its proper divisors (2571037794).

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

1816181406 is a wasteful number, since it uses less digits than its factorization.

1816181406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24310 (or 24304 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 1816181406 is about 42616.6799035307. The cubic root of 1816181406 is about 1220.0746630826.

Adding to 1816181406 its reverse (6041816181), we get a palindrome (7857997587).

The spelling of 1816181406 in words is "one billion, eight hundred sixteen million, one hundred eighty-one thousand, four hundred six".