21113213331 has 48 divisors (see below), whose sum is σ = 34769539584. Its totient is φ = 11141991168.

The previous prime is 21113213243. The next prime is 21113213339. The reversal of 21113213331 is 13331231112.

It is a happy number.

It is not a de Polignac number, because 21113213331 - 2¹⁹ = 21112689043 is a prime.

It is a super-2 number, since 2×21113213331² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a junction number, because it is equal to n+sod(n) for n = 21113213298 and 21113213307.

It is not an unprimeable number, because it can be changed into a prime (21113213339) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 380215 + ... + 432191.

It is an arithmetic number, because the mean of its divisors is an integer number (724365408).

Almost surely, 2^21113213331 is an apocalyptic number.

21113213331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21113213331 is a deficient number, since it is larger than the sum of its proper divisors (13656326253).

21113213331 is a wasteful number, since it uses less digits than its factorization.

21113213331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52068 (or 52039 counting only the distinct ones).

The product of its digits is 324, while the sum is 21.

Adding to 21113213331 its reverse (13331231112), we get a palindrome (34444444443).

The spelling of 21113213331 in words is "twenty-one billion, one hundred thirteen million, two hundred thirteen thousand, three hundred thirty-one".