215105243 has 4 divisors (see below), whose sum is σ = 215962488. Its totient is φ = 214248000.

The previous prime is 215105239. The next prime is 215105279. The reversal of 215105243 is 342501512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 215105243 - 2² = 215105239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215105843) 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 3 ways as a sum of consecutive naturals, for example, 428246 + ... + 428747.

It is an arithmetic number, because the mean of its divisors is an integer number (53990622).

Almost surely, 2^215105243 is an apocalyptic number.

215105243 is a deficient number, since it is larger than the sum of its proper divisors (857245).

215105243 is an equidigital number, since it uses as much as digits as its factorization.

215105243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 857244.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 215105243 is about 14666.4666160599. The cubic root of 215105243 is about 599.1703746948.

Adding to 215105243 its reverse (342501512), we get a palindrome (557606755).

The spelling of 215105243 in words is "two hundred fifteen million, one hundred five thousand, two hundred forty-three".