216803440 has 80 divisors (see below), whose sum is σ = 587908800. Its totient is φ = 74323200.

The previous prime is 216803437. The next prime is 216803453. The reversal of 216803440 is 44308612.

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 = 216803399 and 216803408.

It is a congruent number.

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, 23490 + ... + 31390.

It is an arithmetic number, because the mean of its divisors is an integer number (7348860).

Almost surely, 2^216803440 is an apocalyptic number.

216803440 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 216803440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (293954400).

216803440 is an abundant number, since it is smaller than the sum of its proper divisors (371105360).

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

216803440 is an equidigital number, since it uses as much as digits as its factorization.

216803440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7935 (or 7915 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 216803440 is about 14724.2466700338. The cubic root of 216803440 is about 600.7430054510.

The spelling of 216803440 in words is "two hundred sixteen million, eight hundred three thousand, four hundred forty".