18481990 has 32 divisors (see below), whose sum is σ = 34810560. Its totient is φ = 7056000.

The previous prime is 18481987. The next prime is 18481997. The reversal of 18481990 is 9918481.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18481997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28975 + ... + 29605.

It is an arithmetic number, because the mean of its divisors is an integer number (1087830).

Almost surely, 2^18481990 is an apocalyptic number.

18481990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18481990 is a deficient number, since it is larger than the sum of its proper divisors (16328570).

18481990 is a wasteful number, since it uses less digits than its factorization.

18481990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768.

The product of its (nonzero) digits is 20736, while the sum is 40.

The square root of 18481990 is about 4299.0685037575. The cubic root of 18481990 is about 264.3927712645.

The spelling of 18481990 in words is "eighteen million, four hundred eighty-one thousand, nine hundred ninety".