8181816 has 16 divisors (see below), whose sum is σ = 20454600. Its totient is φ = 2727264.

The previous prime is 8181809. The next prime is 8181821. The reversal of 8181816 is 6181818.

It is a super-2 number, since 2×8181816² = 133884226115712, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170431 + ... + 170478.

Almost surely, 2^8181816 is an apocalyptic number.

It is an amenable number.

8181816 is an abundant number, since it is smaller than the sum of its proper divisors (12272784).

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

8181816 is a wasteful number, since it uses less digits than its factorization.

8181816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340918 (or 340914 counting only the distinct ones).

The product of its digits is 3072, while the sum is 33.

The square root of 8181816 is about 2860.3873863517. The cubic root of 8181816 is about 201.5037979527.

The spelling of 8181816 in words is "eight million, one hundred eighty-one thousand, eight hundred sixteen".