216231840 has 432 divisors, whose sum is σ = 870544584. Its totient is φ = 48660480.

The previous prime is 216231817. The next prime is 216231871. The reversal of 216231840 is 48132612.

216231840 is a `hidden beast` number, since 21 + 623 + 18 + 4 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 199487376 + 16744464 = 14124^2 + 4092^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2962044 + ... + 2962116.

Almost surely, 2^216231840 is an apocalyptic number.

216231840 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 216231840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435272292).

216231840 is an abundant number, since it is smaller than the sum of its proper divisors (654312744).

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

216231840 is a wasteful number, since it uses less digits than its factorization.

216231840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 216231840 is about 14704.8236983651. The cubic root of 216231840 is about 600.2145899095.

The spelling of 216231840 in words is "two hundred sixteen million, two hundred thirty-one thousand, eight hundred forty".