18893988 has 36 divisors (see below), whose sum is σ = 48304620. Its totient is φ = 6226176.

The previous prime is 18893981. The next prime is 18894019. The reversal of 18893988 is 88939881.

It can be written as a sum of positive squares in 2 ways, for example, as 11009124 + 7884864 = 3318^2 + 2808^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (18893981) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 256 + ... + 6152.

It is an arithmetic number, because the mean of its divisors is an integer number (1341795).

Almost surely, 2^18893988 is an apocalyptic number.

18893988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18893988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24152310).

18893988 is an abundant number, since it is smaller than the sum of its proper divisors (29410632).

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

18893988 is a wasteful number, since it uses less digits than its factorization.

18893988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5996 (or 5991 counting only the distinct ones).

The product of its digits is 995328, while the sum is 54.

The square root of 18893988 is about 4346.7215231712. The cubic root of 18893988 is about 266.3429537240.

It can be divided in two parts, 18893 and 988, that added together give a square (19881 = 141²).

The spelling of 18893988 in words is "eighteen million, eight hundred ninety-three thousand, nine hundred eighty-eight".