18380646 has 24 divisors (see below), whose sum is σ = 40421784. Its totient is φ = 6035040.

The previous prime is 18380641. The next prime is 18380647. The reversal of 18380646 is 64608381.

It is a happy number.

18380646 is a `hidden beast` number, since 1 + 8 + 3 + 8 + 0 + 646 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 18380646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18380641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6415 + ... + 8826.

It is an arithmetic number, because the mean of its divisors is an integer number (1684241).

Almost surely, 2^18380646 is an apocalyptic number.

18380646 is an abundant number, since it is smaller than the sum of its proper divisors (22041138).

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

18380646 is a wasteful number, since it uses less digits than its factorization.

18380646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15316 (or 15313 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 18380646 is about 4287.2655621037. The cubic root of 18380646 is about 263.9086288482.

The spelling of 18380646 in words is "eighteen million, three hundred eighty thousand, six hundred forty-six".