21344131205 has 4 divisors (see below), whose sum is σ = 25612957452. Its totient is φ = 17075304960.

The previous prime is 21344131201. The next prime is 21344131273. The reversal of 21344131205 is 50213144312.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10306107361 + 11038023844 = 101519^2 + 105062^2 .

It is not a de Polignac number, because 21344131205 - 2² = 21344131201 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344131201) 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, 2134413116 + ... + 2134413125.

It is an arithmetic number, because the mean of its divisors is an integer number (6403239363).

Almost surely, 2^21344131205 is an apocalyptic number.

It is an amenable number.

21344131205 is a deficient number, since it is larger than the sum of its proper divisors (4268826247).

21344131205 is an equidigital number, since it uses as much as digits as its factorization.

21344131205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4268826246.

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 21344131205 its reverse (50213144312), we get a palindrome (71557275517).

The spelling of 21344131205 in words is "twenty-one billion, three hundred forty-four million, one hundred thirty-one thousand, two hundred five".