28336668721 has 2 divisors, whose sum is σ = 28336668722. Its totient is φ = 28336668720.

The previous prime is 28336668691. The next prime is 28336668751. The reversal of 28336668721 is 12786663382.

It is a balanced prime because it is at equal distance from previous prime (28336668691) and next prime (28336668751).

It can be written as a sum of positive squares in only one way, i.e., 26887800625 + 1448868096 = 163975^2 + 38064^2 .

It is a cyclic number.

It is not a de Polignac number, because 28336668721 - 2¹⁵ = 28336635953 is a prime.

It is not a weakly prime, because it can be changed into another prime (28336668751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14168334360 + 14168334361.

It is an arithmetic number, because the mean of its divisors is an integer number (14168334361).

Almost surely, 2^28336668721 is an apocalyptic number.

It is an amenable number.

28336668721 is a deficient number, since it is larger than the sum of its proper divisors (1).

28336668721 is an equidigital number, since it uses as much as digits as its factorization.

28336668721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3483648, while the sum is 52.

The spelling of 28336668721 in words is "twenty-eight billion, three hundred thirty-six million, six hundred sixty-eight thousand, seven hundred twenty-one".