18307890 has 32 divisors (see below), whose sum is σ = 48821760. Its totient is φ = 4882032.

The previous prime is 18307831. The next prime is 18307907. The reversal of 18307890 is 9870381.

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

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 33634 + ... + 34173.

It is an arithmetic number, because the mean of its divisors is an integer number (1525680).

Almost surely, 2^18307890 is an apocalyptic number.

18307890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18307890 is an abundant number, since it is smaller than the sum of its proper divisors (30513870).

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

18307890 is a wasteful number, since it uses less digits than its factorization.

18307890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67823 (or 67817 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 18307890 is about 4278.7720201011. The cubic root of 18307890 is about 263.5599590866.

The spelling of 18307890 in words is "eighteen million, three hundred seven thousand, eight hundred ninety".