21305432501113 has 4 divisors (see below), whose sum is σ = 21359098578340. Its totient is φ = 21251766423888.

The previous prime is 21305432501107. The next prime is 21305432501131. The reversal of 21305432501113 is 31110523450312.

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 16939455683049 + 4365976818064 = 4115757^2 + 2089492^2 .

It is a cyclic number.

It is not a de Polignac number, because 21305432501113 - 2²⁵ = 21305398946681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21305432505113) 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, 26833038018 + ... + 26833038811.

It is an arithmetic number, because the mean of its divisors is an integer number (5339774644585).

Almost surely, 2^{21305432501113} is an apocalyptic number.

It is an amenable number.

21305432501113 is a deficient number, since it is larger than the sum of its proper divisors (53666077227).

21305432501113 is an equidigital number, since it uses as much as digits as its factorization.

21305432501113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53666077226.

The product of its (nonzero) digits is 10800, while the sum is 31.

Adding to 21305432501113 its reverse (31110523450312), we get a palindrome (52415955951425).

The spelling of 21305432501113 in words is "twenty-one trillion, three hundred five billion, four hundred thirty-two million, five hundred one thousand, one hundred thirteen".