215531055 has 24 divisors (see below), whose sum is σ = 382702320. Its totient is φ = 112145280.

The previous prime is 215531051. The next prime is 215531081. The reversal of 215531055 is 550135512.

215531055 is a `hidden beast` number, since 2 + 1 + 553 + 105 + 5 = 666.

It is not a de Polignac number, because 215531055 - 2² = 215531051 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215531051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 56565 + ... + 60254.

It is an arithmetic number, because the mean of its divisors is an integer number (15945930).

Almost surely, 2^215531055 is an apocalyptic number.

215531055 is a deficient number, since it is larger than the sum of its proper divisors (167171265).

215531055 is a wasteful number, since it uses less digits than its factorization.

215531055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116871 (or 116868 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 27.

The square root of 215531055 is about 14680.9759552967. The cubic root of 215531055 is about 599.5654770590.

Adding to 215531055 its reverse (550135512), we get a palindrome (765666567).

The spelling of 215531055 in words is "two hundred fifteen million, five hundred thirty-one thousand, fifty-five".