28121020113 has 4 divisors (see below), whose sum is σ = 37494693488. Its totient is φ = 18747346740.

The previous prime is 28121020097. The next prime is 28121020117. The reversal of 28121020113 is 31102012182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28121020113 - 2⁴ = 28121020097 is a prime.

It is a super-3 number, since 3×28121020113³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28121020113.

It is not an unprimeable number, because it can be changed into a prime (28121020117) 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, 4686836683 + ... + 4686836688.

It is an arithmetic number, because the mean of its divisors is an integer number (9373673372).

Almost surely, 2^28121020113 is an apocalyptic number.

It is an amenable number.

28121020113 is a deficient number, since it is larger than the sum of its proper divisors (9373673375).

28121020113 is an equidigital number, since it uses as much as digits as its factorization.

28121020113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9373673374.

The product of its (nonzero) digits is 192, while the sum is 21.

Adding to 28121020113 its reverse (31102012182), we get a palindrome (59223032295).

The spelling of 28121020113 in words is "twenty-eight billion, one hundred twenty-one million, twenty thousand, one hundred thirteen".