19998240 has 96 divisors (see below), whose sum is σ = 64120896. Its totient is φ = 5237760.

The previous prime is 19998229. The next prime is 19998263. The reversal of 19998240 is 4289991.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 19998192 and 19998201.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28939 + ... + 29621.

It is an arithmetic number, because the mean of its divisors is an integer number (667926).

Almost surely, 2^19998240 is an apocalyptic number.

19998240 is a gapful number since it is divisible by the number (10) 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 19998240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32060448).

19998240 is an abundant number, since it is smaller than the sum of its proper divisors (44122656).

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

19998240 is a wasteful number, since it uses less digits than its factorization.

19998240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762 (or 754 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 19998240 is about 4471.9391766883. The cubic root of 19998240 is about 271.4337991342.

The spelling of 19998240 in words is "nineteen million, nine hundred ninety-eight thousand, two hundred forty".