21232331021 has 32 divisors (see below), whose sum is σ = 24604397568. Its totient is φ = 18132459840.

The previous prime is 21232331017. The next prime is 21232331023. The reversal of 21232331021 is 12013323212.

It is not a de Polignac number, because 21232331021 - 2² = 21232331017 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21232330984 and 21232331002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232331023) 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 31 ways as a sum of consecutive naturals, for example, 6219311 + ... + 6222723.

It is an arithmetic number, because the mean of its divisors is an integer number (768887424).

Almost surely, 2^21232331021 is an apocalyptic number.

It is an amenable number.

21232331021 is a deficient number, since it is larger than the sum of its proper divisors (3372066547).

21232331021 is a wasteful number, since it uses less digits than its factorization.

21232331021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3881.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21232331021 its reverse (12013323212), we get a palindrome (33245654233).

It can be divided in two parts, 21232 and 331021, that added together give a palindrome (352253).

The spelling of 21232331021 in words is "twenty-one billion, two hundred thirty-two million, three hundred thirty-one thousand, twenty-one".