18381490 has 16 divisors (see below), whose sum is σ = 33229440. Its totient is φ = 7320880.

The previous prime is 18381469. The next prime is 18381491. The reversal of 18381490 is 9418381.

It is a happy number.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (18381491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1456 + ... + 6235.

It is an arithmetic number, because the mean of its divisors is an integer number (2076840).

Almost surely, 2^18381490 is an apocalyptic number.

18381490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18381490 is a deficient number, since it is larger than the sum of its proper divisors (14847950).

18381490 is a wasteful number, since it uses less digits than its factorization.

18381490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7937.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 18381490 is about 4287.3639920119. The cubic root of 18381490 is about 263.9126681598.

The spelling of 18381490 in words is "eighteen million, three hundred eighty-one thousand, four hundred ninety".