215980032721 has 4 divisors (see below), whose sum is σ = 220055127732. Its totient is φ = 211904937712.

The previous prime is 215980032689. The next prime is 215980032731. The reversal of 215980032721 is 127230089512.

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 155409408400 + 60570624321 = 394220^2 + 246111^2 .

It is a cyclic number.

It is not a de Polignac number, because 215980032721 - 2⁵ = 215980032689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215980032731) 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, 2037547426 + ... + 2037547531.

It is an arithmetic number, because the mean of its divisors is an integer number (55013781933).

Almost surely, 2^215980032721 is an apocalyptic number.

It is an amenable number.

215980032721 is a deficient number, since it is larger than the sum of its proper divisors (4075095011).

215980032721 is an equidigital number, since it uses as much as digits as its factorization.

215980032721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4075095010.

The product of its (nonzero) digits is 60480, while the sum is 40.

The spelling of 215980032721 in words is "two hundred fifteen billion, nine hundred eighty million, thirty-two thousand, seven hundred twenty-one".