19800240 has 160 divisors (see below), whose sum is σ = 68138496. Its totient is φ = 4730880.

The previous prime is 19800239. The next prime is 19800241. The reversal of 19800240 is 4200891.

It is an interprime number because it is at equal distance from previous prime (19800239) and next prime (19800241).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 19800240.

It is not an unprimeable number, because it can be changed into a prime (19800241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 93735 + ... + 93945.

Almost surely, 2^19800240 is an apocalyptic number.

19800240 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 19800240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34069248).

19800240 is an abundant number, since it is smaller than the sum of its proper divisors (48338256).

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

19800240 is a wasteful number, since it uses less digits than its factorization.

19800240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267 (or 261 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 19800240 is about 4449.7460601702. The cubic root of 19800240 is about 270.5350159615.

The spelling of 19800240 in words is "nineteen million, eight hundred thousand, two hundred forty".