21544212313 has 8 divisors (see below), whose sum is σ = 23767349256. Its totient is φ = 19401916800.

The previous prime is 21544212307. The next prime is 21544212367. The reversal of 21544212313 is 31321244512.

It can be written as a sum of positive squares in 4 ways, for example, as 475109209 + 21069103104 = 21797^2 + 145152^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21544212313 - 2²⁹ = 21007341401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21544212713) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20209798 + ... + 20210863.

It is an arithmetic number, because the mean of its divisors is an integer number (2970918657).

Almost surely, 2^21544212313 is an apocalyptic number.

It is an amenable number.

21544212313 is a deficient number, since it is larger than the sum of its proper divisors (2223136943).

21544212313 is a wasteful number, since it uses less digits than its factorization.

21544212313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40420715.

The product of its digits is 5760, while the sum is 28.

Adding to 21544212313 its reverse (31321244512), we get a palindrome (52865456825).

The spelling of 21544212313 in words is "twenty-one billion, five hundred forty-four million, two hundred twelve thousand, three hundred thirteen".