855559955561 has 2 divisors, whose sum is σ = 855559955562. Its totient is φ = 855559955560.

The previous prime is 855559955539. The next prime is 855559955581. The reversal of 855559955561 is 165559955558.

855559955561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 854249153536 + 1310802025 = 924256^2 + 36205^2 .

It is a cyclic number.

It is not a de Polignac number, because 855559955561 - 2¹⁰ = 855559954537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 855559955491 and 855559955500.

It is not a weakly prime, because it can be changed into another prime (855559955521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427779977780 + 427779977781.

It is an arithmetic number, because the mean of its divisors is an integer number (427779977781).

Almost surely, 2^855559955561 is an apocalyptic number.

It is an amenable number.

855559955561 is a deficient number, since it is larger than the sum of its proper divisors (1).

855559955561 is an equidigital number, since it uses as much as digits as its factorization.

855559955561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 303750000, while the sum is 68.

The spelling of 855559955561 in words is "eight hundred fifty-five billion, five hundred fifty-nine million, nine hundred fifty-five thousand, five hundred sixty-one".