215513215 has 4 divisors (see below), whose sum is σ = 258615864. Its totient is φ = 172410568.

The previous prime is 215513203. The next prime is 215513251. The reversal of 215513215 is 512315512.

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 215513215 - 2¹³ = 215505023 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 215513215.

It is a congruent number.

It is an unprimeable number.

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, 21551317 + ... + 21551326.

It is an arithmetic number, because the mean of its divisors is an integer number (64653966).

Almost surely, 2^215513215 is an apocalyptic number.

215513215 is a deficient number, since it is larger than the sum of its proper divisors (43102649).

215513215 is an equidigital number, since it uses as much as digits as its factorization.

215513215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43102648.

The product of its digits is 1500, while the sum is 25.

The square root of 215513215 is about 14680.3683536892. The cubic root of 215513215 is about 599.5489341324.

Adding to 215513215 its reverse (512315512), we get a palindrome (727828727).

The spelling of 215513215 in words is "two hundred fifteen million, five hundred thirteen thousand, two hundred fifteen".