65857277221 has 2 divisors, whose sum is σ = 65857277222. Its totient is φ = 65857277220.

The previous prime is 65857277209. The next prime is 65857277249. The reversal of 65857277221 is 12277275856.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46989232900 + 18868044321 = 216770^2 + 137361^2 .

It is a cyclic number.

It is not a de Polignac number, because 65857277221 - 2¹⁷ = 65857146149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65857277251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32928638610 + 32928638611.

It is an arithmetic number, because the mean of its divisors is an integer number (32928638611).

Almost surely, 2^65857277221 is an apocalyptic number.

It is an amenable number.

65857277221 is a deficient number, since it is larger than the sum of its proper divisors (1).

65857277221 is an equidigital number, since it uses as much as digits as its factorization.

65857277221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3292800, while the sum is 52.

The spelling of 65857277221 in words is "sixty-five billion, eight hundred fifty-seven million, two hundred seventy-seven thousand, two hundred twenty-one".