21121132231 has 16 divisors (see below), whose sum is σ = 23343574464. Its totient is φ = 19008152064.

The previous prime is 21121132229. The next prime is 21121132243. The reversal of 21121132231 is 13223112112.

It is not a de Polignac number, because 21121132231 - 2¹ = 21121132229 is a prime.

It is a super-2 number, since 2×21121132231² (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 = 21121132199 and 21121132208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121132211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1508941 + ... + 1522873.

It is an arithmetic number, because the mean of its divisors is an integer number (1458973404).

Almost surely, 2^21121132231 is an apocalyptic number.

21121132231 is a deficient number, since it is larger than the sum of its proper divisors (2222442233).

21121132231 is a wasteful number, since it uses less digits than its factorization.

21121132231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17850.

The product of its digits is 144, while the sum is 19.

Adding to 21121132231 its reverse (13223112112), we get a palindrome (34344244343).

The spelling of 21121132231 in words is "twenty-one billion, one hundred twenty-one million, one hundred thirty-two thousand, two hundred thirty-one".