21132032221 has 4 divisors (see below), whose sum is σ = 21219717244. Its totient is φ = 21044347200.

The previous prime is 21132032219. The next prime is 21132032263. The reversal of 21132032221 is 12223023112.

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 17500644100 + 3631388121 = 132290^2 + 60261^2 .

It is a cyclic number.

It is not a de Polignac number, because 21132032221 - 2¹ = 21132032219 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 (21132036221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43842150 + ... + 43842631.

It is an arithmetic number, because the mean of its divisors is an integer number (5304929311).

Almost surely, 2^21132032221 is an apocalyptic number.

It is an amenable number.

21132032221 is a deficient number, since it is larger than the sum of its proper divisors (87685023).

21132032221 is an equidigital number, since it uses as much as digits as its factorization.

21132032221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87685022.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21132032221 its reverse (12223023112), we get a palindrome (33355055333).

The spelling of 21132032221 in words is "twenty-one billion, one hundred thirty-two million, thirty-two thousand, two hundred twenty-one".