18203816 has 8 divisors (see below), whose sum is σ = 34132170. Its totient is φ = 9101904.

The previous prime is 18203743. The next prime is 18203819. The reversal of 18203816 is 61830281.

It can be written as a sum of positive squares in only one way, i.e., 16434916 + 1768900 = 4054^2 + 1330^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (18203819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1137731 + ... + 1137746.

Almost surely, 2^18203816 is an apocalyptic number.

It is an amenable number.

18203816 is a deficient number, since it is larger than the sum of its proper divisors (15928354).

18203816 is a wasteful number, since it uses less digits than its factorization.

18203816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2275483 (or 2275479 counting only the distinct ones).

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

The square root of 18203816 is about 4266.5930201977. The cubic root of 18203816 is about 263.0595941230.

The spelling of 18203816 in words is "eighteen million, two hundred three thousand, eight hundred sixteen".