21115131321344 has 22 divisors (see below), whose sum is σ = 42209642399304. Its totient is φ = 10557565660160.

The previous prime is 21115131321343. The next prime is 21115131321353. The reversal of 21115131321344 is 44312313151112.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 21115131321344.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115131321343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10310121692 + ... + 10310123739.

Almost surely, 2^{21115131321344} is an apocalyptic number.

It is an amenable number.

21115131321344 is a deficient number, since it is larger than the sum of its proper divisors (21094511077960).

21115131321344 is an equidigital number, since it uses as much as digits as its factorization.

21115131321344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20620245451 (or 20620245433 counting only the distinct ones).

The product of its digits is 8640, while the sum is 32.

Adding to 21115131321344 its reverse (44312313151112), we get a palindrome (65427444472456).

The spelling of 21115131321344 in words is "twenty-one trillion, one hundred fifteen billion, one hundred thirty-one million, three hundred twenty-one thousand, three hundred forty-four".