21426117673 has 4 divisors (see below), whose sum is σ = 21450549700. Its totient is φ = 21401685648.

The previous prime is 21426117623. The next prime is 21426117689. The reversal of 21426117673 is 37671162412.

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 11519299584 + 9906818089 = 107328^2 + 99533^2 .

It is a cyclic number.

It is not a de Polignac number, because 21426117673 - 2²¹ = 21424020521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21426117623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12214698 + ... + 12216451.

It is an arithmetic number, because the mean of its divisors is an integer number (5362637425).

Almost surely, 2^21426117673 is an apocalyptic number.

It is an amenable number.

21426117673 is a deficient number, since it is larger than the sum of its proper divisors (24432027).

21426117673 is an equidigital number, since it uses as much as digits as its factorization.

21426117673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24432026.

The product of its digits is 84672, while the sum is 40.

The spelling of 21426117673 in words is "twenty-one billion, four hundred twenty-six million, one hundred seventeen thousand, six hundred seventy-three".