215631155 has 4 divisors (see below), whose sum is σ = 258757392. Its totient is φ = 172504920.

The previous prime is 215631151. The next prime is 215631167. The reversal of 215631155 is 551136512.

215631155 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 215631155 - 2² = 215631151 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (215631151) 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, 21563111 + ... + 21563120.

It is an arithmetic number, because the mean of its divisors is an integer number (64689348).

Almost surely, 2^215631155 is an apocalyptic number.

215631155 is a deficient number, since it is larger than the sum of its proper divisors (43126237).

215631155 is an equidigital number, since it uses as much as digits as its factorization.

215631155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43126236.

The product of its digits is 4500, while the sum is 29.

The square root of 215631155 is about 14684.3847334507. The cubic root of 215631155 is about 599.6582822705.

Adding to 215631155 its reverse (551136512), we get a palindrome (766767667).

The spelling of 215631155 in words is "two hundred fifteen million, six hundred thirty-one thousand, one hundred fifty-five".