16181816 has 32 divisors (see below), whose sum is σ = 35030880. Its totient is φ = 6864000.

The previous prime is 16181761. The next prime is 16181819. The reversal of 16181816 is 61818161.

16181816 = T₂₉₅ + T₂₉₆ + ... + T₄₉₆.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16181819) 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, 4226 + ... + 7086.

It is an arithmetic number, because the mean of its divisors is an integer number (1094715).

Almost surely, 2^16181816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16181816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17515440).

16181816 is an abundant number, since it is smaller than the sum of its proper divisors (18849064).

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

16181816 is a wasteful number, since it uses less digits than its factorization.

16181816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2975 (or 2971 counting only the distinct ones).

The product of its digits is 2304, while the sum is 32.

The square root of 16181816 is about 4022.6627996888. The cubic root of 16181816 is about 252.9350914325.

Adding to 16181816 its reverse (61818161), we get a palindrome (77999977).

The spelling of 16181816 in words is "sixteen million, one hundred eighty-one thousand, eight hundred sixteen".