18236477 has 6 divisors (see below), whose sum is σ = 21213918. Its totient is φ = 15631224.

The previous prime is 18236473. The next prime is 18236479. The reversal of 18236477 is 77463281.

It can be written as a sum of positive squares in only one way, i.e., 10278436 + 7958041 = 3206^2 + 2821^2 .

It is not a de Polignac number, because 18236477 - 2² = 18236473 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18236477.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18236473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 186038 + ... + 186135.

It is an arithmetic number, because the mean of its divisors is an integer number (3535653).

Almost surely, 2^18236477 is an apocalyptic number.

It is an amenable number.

18236477 is a deficient number, since it is larger than the sum of its proper divisors (2977441).

18236477 is an equidigital number, since it uses as much as digits as its factorization.

18236477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372187 (or 372180 counting only the distinct ones).

The product of its digits is 56448, while the sum is 38.

The square root of 18236477 is about 4270.4188319180. The cubic root of 18236477 is about 263.2168259199.

The spelling of 18236477 in words is "eighteen million, two hundred thirty-six thousand, four hundred seventy-seven".