28364005721 has 2 divisors, whose sum is σ = 28364005722. Its totient is φ = 28364005720.

The previous prime is 28364005603. The next prime is 28364005729. The reversal of 28364005721 is 12750046382.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14504830096 + 13859175625 = 120436^2 + 117725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28364005721 is a prime.

It is not a weakly prime, because it can be changed into another prime (28364005729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14182002860 + 14182002861.

It is an arithmetic number, because the mean of its divisors is an integer number (14182002861).

Almost surely, 2^28364005721 is an apocalyptic number.

It is an amenable number.

28364005721 is a deficient number, since it is larger than the sum of its proper divisors (1).

28364005721 is an equidigital number, since it uses as much as digits as its factorization.

28364005721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 38.

The spelling of 28364005721 in words is "twenty-eight billion, three hundred sixty-four million, five thousand, seven hundred twenty-one".