216819840 has 64 divisors (see below), whose sum is σ = 691119360. Its totient is φ = 57818112.

The previous prime is 216819817. The next prime is 216819847. The reversal of 216819840 is 48918612.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (216819847) 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 7 ways as a sum of consecutive naturals, for example, 54544 + ... + 58383.

It is an arithmetic number, because the mean of its divisors is an integer number (10798740).

Almost surely, 2^216819840 is an apocalyptic number.

216819840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216819840 is an abundant number, since it is smaller than the sum of its proper divisors (474299520).

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

216819840 is a wasteful number, since it uses less digits than its factorization.

216819840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112949 (or 112937 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 216819840 is about 14724.8035640548. The cubic root of 216819840 is about 600.7581527150.

The spelling of 216819840 in words is "two hundred sixteen million, eight hundred nineteen thousand, eight hundred forty".