28321156405 has 4 divisors (see below), whose sum is σ = 33985387692. Its totient is φ = 22656925120.

The previous prime is 28321156403. The next prime is 28321156427. The reversal of 28321156405 is 50465112382.

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 15247063441 + 13074092964 = 123479^2 + 114342^2 .

It is not a de Polignac number, because 28321156405 - 2¹ = 28321156403 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28321156403) 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, 2832115636 + ... + 2832115645.

It is an arithmetic number, because the mean of its divisors is an integer number (8496346923).

Almost surely, 2^28321156405 is an apocalyptic number.

It is an amenable number.

28321156405 is a deficient number, since it is larger than the sum of its proper divisors (5664231287).

28321156405 is an equidigital number, since it uses as much as digits as its factorization.

28321156405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5664231286.

The product of its (nonzero) digits is 57600, while the sum is 37.

Adding to 28321156405 its reverse (50465112382), we get a palindrome (78786268787).

The spelling of 28321156405 in words is "twenty-eight billion, three hundred twenty-one million, one hundred fifty-six thousand, four hundred five".