1815816 has 16 divisors (see below), whose sum is σ = 4539600. Its totient is φ = 605264.

The previous prime is 1815809. The next prime is 1815817. The reversal of 1815816 is 6185181.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1815817) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37806 + ... + 37853.

It is an arithmetic number, because the mean of its divisors is an integer number (283725).

2^1815816 is an apocalyptic number.

It is an amenable number.

1815816 is an abundant number, since it is smaller than the sum of its proper divisors (2723784).

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

1815816 is a wasteful number, since it uses less digits than its factorization.

1815816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75668 (or 75664 counting only the distinct ones).

The product of its digits is 1920, while the sum is 30.

The square root of 1815816 is about 1347.5221705041. The cubic root of 1815816 is about 121.9992833426. Note that the first 3 decimals are identical.

The spelling of 1815816 in words is "one million, eight hundred fifteen thousand, eight hundred sixteen".