18981648 has 80 divisors (see below), whose sum is σ = 62277760. Its totient is φ = 5422464.

The previous prime is 18981617. The next prime is 18981649. The reversal of 18981648 is 84618981.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18981649) 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, 115 + ... + 6162.

It is an arithmetic number, because the mean of its divisors is an integer number (778472).

Almost surely, 2^18981648 is an apocalyptic number.

18981648 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 18981648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31138880).

18981648 is an abundant number, since it is smaller than the sum of its proper divisors (43296112).

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

18981648 is a wasteful number, since it uses less digits than its factorization.

18981648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6301 (or 6289 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The square root of 18981648 is about 4356.7933161902. The cubic root of 18981648 is about 266.7542240260.

The spelling of 18981648 in words is "eighteen million, nine hundred eighty-one thousand, six hundred forty-eight".