215115840 has 168 divisors, whose sum is σ = 747586008. Its totient is φ = 56770560.

The previous prime is 215115839. The next prime is 215115863. The reversal of 215115840 is 48511512.

It can be written as a sum of positive squares in 4 ways, for example, as 4981824 + 210134016 = 2232^2 + 14496^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 325110 + ... + 325770.

Almost surely, 2^215115840 is an apocalyptic number.

215115840 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 215115840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373793004).

215115840 is an abundant number, since it is smaller than the sum of its proper divisors (532470168).

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

215115840 is a wasteful number, since it uses less digits than its factorization.

215115840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The square root of 215115840 is about 14666.8278779019. The cubic root of 215115840 is about 599.1802137610.

The spelling of 215115840 in words is "two hundred fifteen million, one hundred fifteen thousand, eight hundred forty".