28172216357 has 2 divisors, whose sum is σ = 28172216358. Its totient is φ = 28172216356.

The previous prime is 28172216249. The next prime is 28172216377. The reversal of 28172216357 is 75361227182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27017168161 + 1155048196 = 164369^2 + 33986^2 .

It is a cyclic number.

It is not a de Polignac number, because 28172216357 - 2²⁴ = 28155439141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28172216377) 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, 14086108178 + 14086108179.

It is an arithmetic number, because the mean of its divisors is an integer number (14086108179).

Almost surely, 2^28172216357 is an apocalyptic number.

It is an amenable number.

28172216357 is a deficient number, since it is larger than the sum of its proper divisors (1).

28172216357 is an equidigital number, since it uses as much as digits as its factorization.

28172216357 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282240, while the sum is 44.

The spelling of 28172216357 in words is "twenty-eight billion, one hundred seventy-two million, two hundred sixteen thousand, three hundred fifty-seven".