21131212413 has 48 divisors (see below), whose sum is σ = 30541245696. Its totient is φ = 12981346560.

The previous prime is 21131212369. The next prime is 21131212423. The reversal of 21131212413 is 31421213112.

It is not a de Polignac number, because 21131212413 - 2¹⁰ = 21131211389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21131212413.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131212423) 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, 4945468 + ... + 4949738.

It is an arithmetic number, because the mean of its divisors is an integer number (636275952).

Almost surely, 2^21131212413 is an apocalyptic number.

It is an amenable number.

21131212413 is a deficient number, since it is larger than the sum of its proper divisors (9410033283).

21131212413 is a wasteful number, since it uses less digits than its factorization.

21131212413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4422 (or 4393 counting only the distinct ones).

The product of its digits is 288, while the sum is 21.

Adding to 21131212413 its reverse (31421213112), we get a palindrome (52552425525).

The spelling of 21131212413 in words is "twenty-one billion, one hundred thirty-one million, two hundred twelve thousand, four hundred thirteen".