28306267021 has 4 divisors (see below), whose sum is σ = 28310954112. Its totient is φ = 28301579932.

The previous prime is 28306267019. The next prime is 28306267043. The reversal of 28306267021 is 12076260382.

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 a cyclic number.

It is not a de Polignac number, because 28306267021 - 2¹ = 28306267019 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 (28306267001) 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, 2334475 + ... + 2346568.

It is an arithmetic number, because the mean of its divisors is an integer number (7077738528).

Almost surely, 2^28306267021 is an apocalyptic number.

It is an amenable number.

28306267021 is a deficient number, since it is larger than the sum of its proper divisors (4687091).

28306267021 is an equidigital number, since it uses as much as digits as its factorization.

28306267021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4687090.

The product of its (nonzero) digits is 48384, while the sum is 37.

The spelling of 28306267021 in words is "twenty-eight billion, three hundred six million, two hundred sixty-seven thousand, twenty-one".