28201202121 has 4 divisors (see below), whose sum is σ = 37601602832. Its totient is φ = 18800801412.

The previous prime is 28201202093. The next prime is 28201202147. The reversal of 28201202121 is 12120210282.

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 28201202121 - 2¹³ = 28201193929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28201202191) 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, 4700200351 + ... + 4700200356.

It is an arithmetic number, because the mean of its divisors is an integer number (9400400708).

Almost surely, 2^28201202121 is an apocalyptic number.

It is an amenable number.

28201202121 is a deficient number, since it is larger than the sum of its proper divisors (9400400711).

28201202121 is an equidigital number, since it uses as much as digits as its factorization.

28201202121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9400400710.

The product of its (nonzero) digits is 256, while the sum is 21.

The spelling of 28201202121 in words is "twenty-eight billion, two hundred one million, two hundred two thousand, one hundred twenty-one".