215252404021 has 8 divisors (see below), whose sum is σ = 217396832184. Its totient is φ = 213108235200.

The previous prime is 215252403941. The next prime is 215252404033. The reversal of 215252404021 is 120404252512.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 196377491025 + 18874912996 = 443145^2 + 137386^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215252404021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215252404051) 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 7 ways as a sum of consecutive naturals, for example, 1897515 + ... + 2007751.

It is an arithmetic number, because the mean of its divisors is an integer number (27174604023).

Almost surely, 2^215252404021 is an apocalyptic number.

It is an amenable number.

215252404021 is a deficient number, since it is larger than the sum of its proper divisors (2144428163).

215252404021 is a wasteful number, since it uses less digits than its factorization.

215252404021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129671.

The product of its (nonzero) digits is 6400, while the sum is 28.

Adding to 215252404021 its reverse (120404252512), we get a palindrome (335656656533).

The spelling of 215252404021 in words is "two hundred fifteen billion, two hundred fifty-two million, four hundred four thousand, twenty-one".