216420400 has 120 divisors (see below), whose sum is σ = 610580960. Its totient is φ = 72161280.

The previous prime is 216420397. The next prime is 216420403. The reversal of 216420400 is 4024612.

It is an interprime number because it is at equal distance from previous prime (216420397) and next prime (216420403).

It is not an unprimeable number, because it can be changed into a prime (216420403) 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 23 ways as a sum of consecutive naturals, for example, 102556 + ... + 104644.

Almost surely, 2^216420400 is an apocalyptic number.

216420400 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 216420400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305290480).

216420400 is an abundant number, since it is smaller than the sum of its proper divisors (394160560).

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

216420400 is a wasteful number, since it uses less digits than its factorization.

216420400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2151 (or 2140 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 216420400 is about 14711.2338027781. The cubic root of 216420400 is about 600.3890069940.

The spelling of 216420400 in words is "two hundred sixteen million, four hundred twenty thousand, four hundred".