21111425513 has 4 divisors (see below), whose sum is σ = 21111972228. Its totient is φ = 21110878800.

The previous prime is 21111425459. The next prime is 21111425551. The reversal of 21111425513 is 31552411112.

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 7397376064 + 13714049449 = 86008^2 + 117107^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111425513 - 2¹⁰ = 21111424489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111425593) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210638 + ... + 294263.

It is an arithmetic number, because the mean of its divisors is an integer number (5277993057).

Almost surely, 2^21111425513 is an apocalyptic number.

It is an amenable number.

21111425513 is a deficient number, since it is larger than the sum of its proper divisors (546715).

21111425513 is an equidigital number, since it uses as much as digits as its factorization.

21111425513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546714.

The product of its digits is 1200, while the sum is 26.

Adding to 21111425513 its reverse (31552411112), we get a palindrome (52663836625).

The spelling of 21111425513 in words is "twenty-one billion, one hundred eleven million, four hundred twenty-five thousand, five hundred thirteen".