215978064 has 80 divisors (see below), whose sum is σ = 600586560. Its totient is φ = 66631680.

The previous prime is 215978041. The next prime is 215978089. The reversal of 215978064 is 460879512.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 47607 + ... + 51945.

It is an arithmetic number, because the mean of its divisors is an integer number (7507332).

Almost surely, 2^215978064 is an apocalyptic number.

215978064 is a gapful number since it is divisible by the number (24) 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 215978064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (300293280).

215978064 is an abundant number, since it is smaller than the sum of its proper divisors (384608496).

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

215978064 is a wasteful number, since it uses less digits than its factorization.

215978064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4428 (or 4422 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The square root of 215978064 is about 14696.1921598760. The cubic root of 215978064 is about 599.9796882013.

The spelling of 215978064 in words is "two hundred fifteen million, nine hundred seventy-eight thousand, sixty-four".