20312032221 has 12 divisors (see below), whose sum is σ = 31596494748. Its totient is φ = 12499712064.

The previous prime is 20312032217. The next prime is 20312032229. The reversal of 20312032221 is 12223021302.

20312032221 is a `hidden beast` number, since 203 + 120 + 322 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6420816900 + 13891215321 = 80130^2 + 117861^2 .

It is not a de Polignac number, because 20312032221 - 2² = 20312032217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20312032194 and 20312032203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20312032229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 86803440 + ... + 86803673.

It is an arithmetic number, because the mean of its divisors is an integer number (2633041229).

Almost surely, 2^20312032221 is an apocalyptic number.

It is an amenable number.

20312032221 is a deficient number, since it is larger than the sum of its proper divisors (11284462527).

20312032221 is a wasteful number, since it uses less digits than its factorization.

20312032221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173607132 (or 173607129 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 20312032221 its reverse (12223021302), we get a palindrome (32535053523).

The spelling of 20312032221 in words is "twenty billion, three hundred twelve million, thirty-two thousand, two hundred twenty-one".