215400064 has 64 divisors (see below), whose sum is σ = 495720000. Its totient is φ = 92139520.

The previous prime is 215400061. The next prime is 215400067. The reversal of 215400064 is 460004512.

215400064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (215400061) and next prime (215400067).

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

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (215400061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19437 + ... + 28435.

It is an arithmetic number, because the mean of its divisors is an integer number (7745625).

Almost surely, 2^215400064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 215400064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247860000).

215400064 is an abundant number, since it is smaller than the sum of its proper divisors (280319936).

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

215400064 is a wasteful number, since it uses less digits than its factorization.

215400064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9041 (or 9029 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 215400064 is about 14676.5140275203. The cubic root of 215400064 is about 599.4439886151.

Adding to 215400064 its reverse (460004512), we get a palindrome (675404576).

The spelling of 215400064 in words is "two hundred fifteen million, four hundred thousand, sixty-four".