215506240 has 28 divisors (see below), whose sum is σ = 513174996. Its totient is φ = 86202368.

The previous prime is 215506231. The next prime is 215506259. The reversal of 215506240 is 42605512.

It can be written as a sum of positive squares in 2 ways, for example, as 68029504 + 147476736 = 8248^2 + 12144^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 336409 + ... + 337048.

Almost surely, 2^215506240 is an apocalyptic number.

215506240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215506240 is an abundant number, since it is smaller than the sum of its proper divisors (297668756).

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

215506240 is an equidigital number, since it uses as much as digits as its factorization.

215506240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673474 (or 673464 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 215506240 is about 14680.1307896081. The cubic root of 215506240 is about 599.5424660079.

The spelling of 215506240 in words is "two hundred fifteen million, five hundred six thousand, two hundred forty".