215146332221 has 4 divisors (see below), whose sum is σ = 215326674012. Its totient is φ = 214965990432.

The previous prime is 215146332187. The next prime is 215146332223. The reversal of 215146332221 is 122233641512.

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

It can be written as a sum of positive squares in 2 ways, for example, as 94872624196 + 120273708025 = 308014^2 + 346805^2 .

It is a cyclic number.

It is not a de Polignac number, because 215146332221 - 2⁶ = 215146332157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215146332223) 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, 90169106 + ... + 90171491.

It is an arithmetic number, because the mean of its divisors is an integer number (53831668503).

Almost surely, 2^215146332221 is an apocalyptic number.

It is an amenable number.

215146332221 is a deficient number, since it is larger than the sum of its proper divisors (180341791).

215146332221 is a wasteful number, since it uses less digits than its factorization.

215146332221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180341790.

The product of its digits is 17280, while the sum is 32.

Adding to 215146332221 its reverse (122233641512), we get a palindrome (337379973733).

The spelling of 215146332221 in words is "two hundred fifteen billion, one hundred forty-six million, three hundred thirty-two thousand, two hundred twenty-one".