84487777778449 has 4 divisors (see below), whose sum is σ = 84586825584436. Its totient is φ = 84388729972464.

The previous prime is 84487777778441. The next prime is 84487777778461. The reversal of 84487777778449 is 94487777778448.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7469250738049 + 77018527040400 = 2732993^2 + 8776020^2 .

It is a cyclic number.

It is not a de Polignac number, because 84487777778449 - 2³ = 84487777778441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84487777778441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49523901714 + ... + 49523903419.

It is an arithmetic number, because the mean of its divisors is an integer number (21146706396109).

Almost surely, 2^{84487777778449} is an apocalyptic number.

It is an amenable number.

84487777778449 is a deficient number, since it is larger than the sum of its proper divisors (99047805987).

84487777778449 is an equidigital number, since it uses as much as digits as its factorization.

84487777778449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99047805986.

The product of its digits is 138784407552, while the sum is 91.

Subtracting 84487777778449 from its reverse (94487777778448), we obtain a palindrome (9999999999999).

The spelling of 84487777778449 in words is "eighty-four trillion, four hundred eighty-seven billion, seven hundred seventy-seven million, seven hundred seventy-eight thousand, four hundred forty-nine".