216571840 has 112 divisors (see below), whose sum is σ = 559941984. Its totient is φ = 79462400.

The previous prime is 216571819. The next prime is 216571871. The reversal of 216571840 is 48175612.

216571840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 216571796 and 216571805.

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, 222555 + ... + 223525.

It is an arithmetic number, because the mean of its divisors is an integer number (4999482).

Almost surely, 2^216571840 is an apocalyptic number.

216571840 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 216571840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279970992).

216571840 is an abundant number, since it is smaller than the sum of its proper divisors (343370144).

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

216571840 is a wasteful number, since it uses less digits than its factorization.

216571840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1046 (or 1036 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 216571840 is about 14716.3799896578. The cubic root of 216571840 is about 600.5290149164.

The spelling of 216571840 in words is "two hundred sixteen million, five hundred seventy-one thousand, eight hundred forty".