215978240 has 72 divisors (see below), whose sum is σ = 534121728. Its totient is φ = 83589120.

The previous prime is 215978239. The next prime is 215978249. The reversal of 215978240 is 42879512.

It is a junction number, because it is equal to n+sod(n) for n = 215978194 and 215978203.

It is not an unprimeable number, because it can be changed into a prime (215978249) 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, 36959 + ... + 42401.

Almost surely, 2^215978240 is an apocalyptic number.

215978240 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 215978240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267060864).

215978240 is an abundant number, since it is smaller than the sum of its proper divisors (318143488).

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

215978240 is an equidigital number, since it uses as much as digits as its factorization.

215978240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5495 (or 5481 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 215978240 is about 14696.1981478204. The cubic root of 215978240 is about 599.9798511752.

The spelling of 215978240 in words is "two hundred fifteen million, nine hundred seventy-eight thousand, two hundred forty".