8556207480781 has 2 divisors, whose sum is σ = 8556207480782. Its totient is φ = 8556207480780.

The previous prime is 8556207480773. The next prime is 8556207480857. The reversal of 8556207480781 is 1870847026558.

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., 7450115660100 + 1106091820681 = 2729490^2 + 1051709^2 .

It is a cyclic number.

It is not a de Polignac number, because 8556207480781 - 2³ = 8556207480773 is a prime.

It is a super-2 number, since 2×8556207480781² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8556207480721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4278103740390 + 4278103740391.

It is an arithmetic number, because the mean of its divisors is an integer number (4278103740391).

Almost surely, 2^{8556207480781} is an apocalyptic number.

It is an amenable number.

8556207480781 is a deficient number, since it is larger than the sum of its proper divisors (1).

8556207480781 is an equidigital number, since it uses as much as digits as its factorization.

8556207480781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30105600, while the sum is 61.

The spelling of 8556207480781 in words is "eight trillion, five hundred fifty-six billion, two hundred seven million, four hundred eighty thousand, seven hundred eighty-one".