215405056 has 40 divisors (see below), whose sum is σ = 431808300. Its totient is φ = 107347968.

The previous prime is 215405041. The next prime is 215405059. The reversal of 215405056 is 650504512.

It can be written as a sum of positive squares in 2 ways, for example, as 205062400 + 10342656 = 14320^2 + 3216^2 .

It is not an unprimeable number, because it can be changed into a prime (215405059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 229420 + ... + 230356.

Almost surely, 2^215405056 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 215405056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215904150).

215405056 is an abundant number, since it is smaller than the sum of its proper divisors (216403244).

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

215405056 is an frugal number, since it uses more digits than its factorization.

215405056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404 (or 1388 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 215405056 is about 14676.6840941679. The cubic root of 215405056 is about 599.4486193802.

Adding to 215405056 its reverse (650504512), we get a palindrome (865909568).

The spelling of 215405056 in words is "two hundred fifteen million, four hundred five thousand, fifty-six".