18801890 has 8 divisors (see below), whose sum is σ = 33843420. Its totient is φ = 7520752.

The previous prime is 18801869. The next prime is 18801899. The reversal of 18801890 is 9810881.

It can be written as a sum of positive squares in 2 ways, for example, as 18722929 + 78961 = 4327^2 + 281^2 .

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

It is a super-2 number, since 2×18801890² = 707022135144200, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18801890.

It is not an unprimeable number, because it can be changed into a prime (18801899) 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, 940085 + ... + 940104.

Almost surely, 2^18801890 is an apocalyptic number.

18801890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18801890 is a deficient number, since it is larger than the sum of its proper divisors (15041530).

18801890 is a wasteful number, since it uses less digits than its factorization.

18801890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1880196.

The product of its (nonzero) digits is 4608, while the sum is 35.

The square root of 18801890 is about 4336.1146202562. The cubic root of 18801890 is about 265.9094892465.

It can be divided in two parts, 18801 and 890, that added together give a palindrome (19691).

The spelling of 18801890 in words is "eighteen million, eight hundred one thousand, eight hundred ninety".