28766820221999 has 2 divisors, whose sum is σ = 28766820222000. Its totient is φ = 28766820221998.

The previous prime is 28766820221989. The next prime is 28766820222059. The reversal of 28766820221999 is 99912202866782.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28766820221999 - 2⁸ = 28766820221743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28766820221939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14383410110999 + 14383410111000.

It is an arithmetic number, because the mean of its divisors is an integer number (14383410111000).

Almost surely, 2^{28766820221999} is an apocalyptic number.

28766820221999 is a deficient number, since it is larger than the sum of its proper divisors (1).

28766820221999 is an equidigital number, since it uses as much as digits as its factorization.

28766820221999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 188116992, while the sum is 71.

The spelling of 28766820221999 in words is "twenty-eight trillion, seven hundred sixty-six billion, eight hundred twenty million, two hundred twenty-one thousand, nine hundred ninety-nine".