18641890 has 8 divisors (see below), whose sum is σ = 33555420. Its totient is φ = 7456752.

The previous prime is 18641863. The next prime is 18641893. The reversal of 18641890 is 9814681.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18122049 + 519841 = 4257^2 + 721^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (18641893) 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 3 ways as a sum of consecutive naturals, for example, 932085 + ... + 932104.

Almost surely, 2^18641890 is an apocalyptic number.

18641890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18641890 is a deficient number, since it is larger than the sum of its proper divisors (14913530).

18641890 is a wasteful number, since it uses less digits than its factorization.

18641890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864196.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 18641890 is about 4317.6255048348. The cubic root of 18641890 is about 265.1530621627.

The spelling of 18641890 in words is "eighteen million, six hundred forty-one thousand, eight hundred ninety".