87655422221 has 2 divisors, whose sum is σ = 87655422222. Its totient is φ = 87655422220.

The previous prime is 87655422163. The next prime is 87655422229. The reversal of 87655422221 is 12222455678.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 86134032196 + 1521390025 = 293486^2 + 39005^2 .

It is a cyclic number.

It is not a de Polignac number, because 87655422221 - 2¹⁸ = 87655160077 is a prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87655422229) 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, 43827711110 + 43827711111.

It is an arithmetic number, because the mean of its divisors is an integer number (43827711111).

Almost surely, 2^87655422221 is an apocalyptic number.

It is an amenable number.

87655422221 is a deficient number, since it is larger than the sum of its proper divisors (1).

87655422221 is an equidigital number, since it uses as much as digits as its factorization.

87655422221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 537600, while the sum is 44.

Adding to 87655422221 its reverse (12222455678), we get a palindrome (99877877899).

The spelling of 87655422221 in words is "eighty-seven billion, six hundred fifty-five million, four hundred twenty-two thousand, two hundred twenty-one".