18023816 has 16 divisors (see below), whose sum is σ = 34433100. Its totient is φ = 8841664.

The previous prime is 18023801. The next prime is 18023821. The reversal of 18023816 is 61832081.

It can be written as a sum of positive squares in 2 ways, for example, as 15288100 + 2735716 = 3910^2 + 1654^2 .

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, 20831 + ... + 21678.

Almost surely, 2^18023816 is an apocalyptic number.

It is an amenable number.

18023816 is a deficient number, since it is larger than the sum of its proper divisors (16409284).

18023816 is a wasteful number, since it uses less digits than its factorization.

18023816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42568 (or 42564 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 18023816 is about 4245.4465018417. The cubic root of 18023816 is about 262.1896728833.

Adding to 18023816 its reverse (61832081), we get a palindrome (79855897).

The spelling of 18023816 in words is "eighteen million, twenty-three thousand, eight hundred sixteen".