18806538 has 24 divisors (see below), whose sum is σ = 38116512. Its totient is φ = 6185824.

The previous prime is 18806531. The next prime is 18806549. The reversal of 18806538 is 83560881.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18806496 and 18806505.

It is not an unprimeable number, because it can be changed into a prime (18806531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 112531 + ... + 112697.

It is an arithmetic number, because the mean of its divisors is an integer number (1588188).

Almost surely, 2^18806538 is an apocalyptic number.

18806538 is an abundant number, since it is smaller than the sum of its proper divisors (19309974).

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

18806538 is a wasteful number, since it uses less digits than its factorization.

18806538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 446 (or 309 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 39.

The square root of 18806538 is about 4336.6505508284. The cubic root of 18806538 is about 265.9313991976.

The spelling of 18806538 in words is "eighteen million, eight hundred six thousand, five hundred thirty-eight".