21232322021 has 4 divisors (see below), whose sum is σ = 21233488032. Its totient is φ = 21231156012.

The previous prime is 21232321991. The next prime is 21232322029. The reversal of 21232322021 is 12022323212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21232322021 - 2¹⁴ = 21232305637 is a prime.

It is a super-2 number, since 2×21232322021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21232321984 and 21232322002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232322029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 555251 + ... + 592256.

It is an arithmetic number, because the mean of its divisors is an integer number (5308372008).

Almost surely, 2^21232322021 is an apocalyptic number.

It is an amenable number.

21232322021 is a deficient number, since it is larger than the sum of its proper divisors (1166011).

21232322021 is a wasteful number, since it uses less digits than its factorization.

21232322021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1166010.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21232322021 its reverse (12022323212), we get a palindrome (33254645233).

The spelling of 21232322021 in words is "twenty-one billion, two hundred thirty-two million, three hundred twenty-two thousand, twenty-one".