216506400 has 288 divisors, whose sum is σ = 787449600. Its totient is φ = 51225600.

The previous prime is 216506399. The next prime is 216506401. The reversal of 216506400 is 4605612.

It is an interprime number because it is at equal distance from previous prime (216506399) and next prime (216506401).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (216506401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1557531 + ... + 1557669.

It is an arithmetic number, because the mean of its divisors is an integer number (2734200).

Almost surely, 2^216506400 is an apocalyptic number.

216506400 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 216506400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (393724800).

216506400 is an abundant number, since it is smaller than the sum of its proper divisors (570943200).

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

216506400 is a wasteful number, since it uses less digits than its factorization.

216506400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 216506400 is about 14714.1564488081. The cubic root of 216506400 is about 600.4685229374.

The spelling of 216506400 in words is "two hundred sixteen million, five hundred six thousand, four hundred".