218113840 has 80 divisors (see below), whose sum is σ = 591962112. Its totient is φ = 73181952.

The previous prime is 218113823. The next prime is 218113867. The reversal of 218113840 is 48311812.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 218113799 and 218113808.

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, 22177 + ... + 30463.

Almost surely, 2^218113840 is an apocalyptic number.

218113840 is a gapful number since it is divisible by the number (20) 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 218113840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295981056).

218113840 is an abundant number, since it is smaller than the sum of its proper divisors (373848272).

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

218113840 is a wasteful number, since it uses less digits than its factorization.

218113840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8354 (or 8348 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 218113840 is about 14768.6776659253. The cubic root of 218113840 is about 601.9509089743.

It can be divided in two parts, 21811 and 3840, that added together give a triangular number (25651 = T₂₂₆).

The spelling of 218113840 in words is "two hundred eighteen million, one hundred thirteen thousand, eight hundred forty".