21210332331 has 4 divisors (see below), whose sum is σ = 28280443112. Its totient is φ = 14140221552.

The previous prime is 21210332317. The next prime is 21210332389. The reversal of 21210332331 is 13323301212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21210332331 - 2¹⁵ = 21210299563 is a prime.

It is a super-2 number, since 2×21210332331² (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 = 21210332298 and 21210332307.

It is not an unprimeable number, because it can be changed into a prime (21210372331) 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, 3535055386 + ... + 3535055391.

It is an arithmetic number, because the mean of its divisors is an integer number (7070110778).

Almost surely, 2^21210332331 is an apocalyptic number.

21210332331 is a deficient number, since it is larger than the sum of its proper divisors (7070110781).

21210332331 is an equidigital number, since it uses as much as digits as its factorization.

21210332331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7070110780.

The product of its (nonzero) digits is 648, while the sum is 21.

Adding to 21210332331 its reverse (13323301212), we get a palindrome (34533633543).

The spelling of 21210332331 in words is "twenty-one billion, two hundred ten million, three hundred thirty-two thousand, three hundred thirty-one".