216420678 has 48 divisors (see below), whose sum is σ = 510634800. Its totient is φ = 65983680.

The previous prime is 216420671. The next prime is 216420683. The reversal of 216420678 is 876024612.

216420678 is a `hidden beast` number, since 2 + 1 + 642 + 0 + 6 + 7 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216420671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 993 + ... + 20828.

It is an arithmetic number, because the mean of its divisors is an integer number (10638225).

Almost surely, 2^216420678 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216420678, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255317400).

216420678 is an abundant number, since it is smaller than the sum of its proper divisors (294214122).

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

216420678 is a wasteful number, since it uses less digits than its factorization.

216420678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21877 (or 21874 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 216420678 is about 14711.2432513367. The cubic root of 216420678 is about 600.3892640679.

The spelling of 216420678 in words is "two hundred sixteen million, four hundred twenty thousand, six hundred seventy-eight".