215204155 has 4 divisors (see below), whose sum is σ = 258244992. Its totient is φ = 172163320.

The previous prime is 215204153. The next prime is 215204161. The reversal of 215204155 is 551402512.

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

It is not a de Polignac number, because 215204155 - 2¹ = 215204153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215204153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21520411 + ... + 21520420.

It is an arithmetic number, because the mean of its divisors is an integer number (64561248).

Almost surely, 2^215204155 is an apocalyptic number.

215204155 is a deficient number, since it is larger than the sum of its proper divisors (43040837).

215204155 is an equidigital number, since it uses as much as digits as its factorization.

215204155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43040836.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 215204155 is about 14669.8382745005. The cubic root of 215204155 is about 599.2621996043.

Adding to 215204155 its reverse (551402512), we get a palindrome (766606667).

The spelling of 215204155 in words is "two hundred fifteen million, two hundred four thousand, one hundred fifty-five".