216212640 has 192 divisors, whose sum is σ = 784546560. Its totient is φ = 49029120.

The previous prime is 216212621. The next prime is 216212657. The reversal of 216212640 is 46212612.

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

It is a self number, because there is not a number n which added to its sum of digits gives 216212640.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 769300 + ... + 769580.

It is an arithmetic number, because the mean of its divisors is an integer number (4086180).

Almost surely, 2^216212640 is an apocalyptic number.

216212640 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 216212640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (392273280).

216212640 is an abundant number, since it is smaller than the sum of its proper divisors (568333920).

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

216212640 is a wasteful number, since it uses less digits than its factorization.

216212640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535 (or 527 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 216212640 is about 14704.1708368748. The cubic root of 216212640 is about 600.1968243155.

The spelling of 216212640 in words is "two hundred sixteen million, two hundred twelve thousand, six hundred forty".