8436377981209 has 2 divisors, whose sum is σ = 8436377981210. Its totient is φ = 8436377981208.

The previous prime is 8436377981197. The next prime is 8436377981257. The reversal of 8436377981209 is 9021897736348.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7273420637184 + 1162957344025 = 2696928^2 + 1078405^2 .

It is a cyclic number.

It is not a de Polignac number, because 8436377981209 - 2²³ = 8436369592601 is a prime.

It is not a weakly prime, because it can be changed into another prime (8436377981299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4218188990604 + 4218188990605.

It is an arithmetic number, because the mean of its divisors is an integer number (4218188990605).

Almost surely, 2^{8436377981209} is an apocalyptic number.

It is an amenable number.

8436377981209 is a deficient number, since it is larger than the sum of its proper divisors (1).

8436377981209 is an equidigital number, since it uses as much as digits as its factorization.

8436377981209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 109734912, while the sum is 67.

The spelling of 8436377981209 in words is "eight trillion, four hundred thirty-six billion, three hundred seventy-seven million, nine hundred eighty-one thousand, two hundred nine".