21012244131 has 4 divisors (see below), whose sum is σ = 28016325512. Its totient is φ = 14008162752.

The previous prime is 21012244027. The next prime is 21012244139. The reversal of 21012244131 is 13144221012.

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

It is not a de Polignac number, because 21012244131 - 2⁷ = 21012244003 is a prime.

It is a super-2 number, since 2×21012244131² (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 = 21012244098 and 21012244107.

It is not an unprimeable number, because it can be changed into a prime (21012244139) 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, 3502040686 + ... + 3502040691.

It is an arithmetic number, because the mean of its divisors is an integer number (7004081378).

Almost surely, 2^21012244131 is an apocalyptic number.

21012244131 is a deficient number, since it is larger than the sum of its proper divisors (7004081381).

21012244131 is an equidigital number, since it uses as much as digits as its factorization.

21012244131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7004081380.

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21012244131 its reverse (13144221012), we get a palindrome (34156465143).

The spelling of 21012244131 in words is "twenty-one billion, twelve million, two hundred forty-four thousand, one hundred thirty-one".