1816994412 has 72 divisors (see below), whose sum is σ = 4718697984. Its totient is φ = 589198176.

The previous prime is 1816994401. The next prime is 1816994423. The reversal of 1816994412 is 2144996181.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1816994401) and next prime (1816994423).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 404893 + ... + 409355.

It is an arithmetic number, because the mean of its divisors is an integer number (65537472).

Almost surely, 2^1816994412 is an apocalyptic number.

1816994412 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1816994412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2359348992).

1816994412 is an abundant number, since it is smaller than the sum of its proper divisors (2901703572).

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

1816994412 is a wasteful number, since it uses less digits than its factorization.

1816994412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4779 (or 4774 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 1816994412 is about 42626.2174254296. The cubic root of 1816994412 is about 1220.2566896952.

The spelling of 1816994412 in words is "one billion, eight hundred sixteen million, nine hundred ninety-four thousand, four hundred twelve".