21403056085 has 4 divisors (see below), whose sum is σ = 25683667308. Its totient is φ = 17122444864.

The previous prime is 21403056047. The next prime is 21403056097. The reversal of 21403056085 is 58065030412.

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 6966072369 + 14436983716 = 83463^2 + 120154^2 .

It is a cyclic number.

It is not a de Polignac number, because 21403056085 - 2¹³ = 21403047893 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21403056085.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2140305604 + ... + 2140305613.

It is an arithmetic number, because the mean of its divisors is an integer number (6420916827).

Almost surely, 2^21403056085 is an apocalyptic number.

It is an amenable number.

21403056085 is a deficient number, since it is larger than the sum of its proper divisors (4280611223).

21403056085 is an equidigital number, since it uses as much as digits as its factorization.

21403056085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4280611222.

The product of its (nonzero) digits is 28800, while the sum is 34.

Adding to 21403056085 its reverse (58065030412), we get a palindrome (79468086497).

The spelling of 21403056085 in words is "twenty-one billion, four hundred three million, fifty-six thousand, eighty-five".