216399872 has 72 divisors (see below), whose sum is σ = 469760256. Its totient is φ = 99090432.

The previous prime is 216399863. The next prime is 216399877. The reversal of 216399872 is 278993612.

It is a happy number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216399877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1703873 + ... + 1703999.

It is an arithmetic number, because the mean of its divisors is an integer number (6524448).

Almost surely, 2^216399872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216399872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (234880128).

216399872 is an abundant number, since it is smaller than the sum of its proper divisors (253360384).

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

216399872 is an frugal number, since it uses more digits than its factorization.

216399872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 142 counting only the distinct ones).

The product of its digits is 326592, while the sum is 47.

The square root of 216399872 is about 14710.5360881240. The cubic root of 216399872 is about 600.3700236092.

The spelling of 216399872 in words is "two hundred sixteen million, three hundred ninety-nine thousand, eight hundred seventy-two".