21812329331 has 4 divisors (see below), whose sum is σ = 23490200832. Its totient is φ = 20134457832.

The previous prime is 21812329313. The next prime is 21812329333. The reversal of 21812329331 is 13392321812.

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

It is a cyclic number.

It is not a de Polignac number, because 21812329331 - 2¹⁸ = 21812067187 is a prime.

It is a super-2 number, since 2×21812329331² (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 = 21812329291 and 21812329300.

It is not an unprimeable number, because it can be changed into a prime (21812329333) 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, 838935731 + ... + 838935756.

It is an arithmetic number, because the mean of its divisors is an integer number (5872550208).

Almost surely, 2^21812329331 is an apocalyptic number.

21812329331 is a deficient number, since it is larger than the sum of its proper divisors (1677871501).

21812329331 is a wasteful number, since it uses less digits than its factorization.

21812329331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1677871500.

The product of its digits is 15552, while the sum is 35.

The spelling of 21812329331 in words is "twenty-one billion, eight hundred twelve million, three hundred twenty-nine thousand, three hundred thirty-one".