21344240131 has 4 divisors (see below), whose sum is σ = 21386674512. Its totient is φ = 21301805752.

The previous prime is 21344240089. The next prime is 21344240179. The reversal of 21344240131 is 13104244312.

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

It is a cyclic number.

It is not a de Polignac number, because 21344240131 - 2¹⁵ = 21344207363 is a prime.

It is a super-2 number, since 2×21344240131² (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 = 21344240096 and 21344240105.

It is not an unprimeable number, because it can be changed into a prime (21344249131) 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, 21216436 + ... + 21217441.

It is an arithmetic number, because the mean of its divisors is an integer number (5346668628).

Almost surely, 2^21344240131 is an apocalyptic number.

21344240131 is a deficient number, since it is larger than the sum of its proper divisors (42434381).

21344240131 is an equidigital number, since it uses as much as digits as its factorization.

21344240131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42434380.

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 21344240131 its reverse (13104244312), we get a palindrome (34448484443).

The spelling of 21344240131 in words is "twenty-one billion, three hundred forty-four million, two hundred forty thousand, one hundred thirty-one".