28312121307 has 4 divisors (see below), whose sum is σ = 37749495080. Its totient is φ = 18874747536.

The previous prime is 28312121287. The next prime is 28312121359. The reversal of 28312121307 is 70312121382.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28312121307 - 2¹¹ = 28312119259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28312128307) 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, 4718686882 + ... + 4718686887.

It is an arithmetic number, because the mean of its divisors is an integer number (9437373770).

Almost surely, 2^28312121307 is an apocalyptic number.

28312121307 is a deficient number, since it is larger than the sum of its proper divisors (9437373773).

28312121307 is an equidigital number, since it uses as much as digits as its factorization.

28312121307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9437373772.

The product of its (nonzero) digits is 4032, while the sum is 30.

Adding to 28312121307 its reverse (70312121382), we get a palindrome (98624242689).

The spelling of 28312121307 in words is "twenty-eight billion, three hundred twelve million, one hundred twenty-one thousand, three hundred seven".