77477878249 has 2 divisors, whose sum is σ = 77477878250. Its totient is φ = 77477878248.

The previous prime is 77477878237. The next prime is 77477878271. The reversal of 77477878249 is 94287877477.

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., 62022415849 + 15455462400 = 249043^2 + 124320^2 .

It is an emirp because it is prime and its reverse (94287877477) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77477878249 is a prime.

It is not a weakly prime, because it can be changed into another prime (77477875249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38738939124 + 38738939125.

It is an arithmetic number, because the mean of its divisors is an integer number (38738939125).

Almost surely, 2^77477878249 is an apocalyptic number.

It is an amenable number.

77477878249 is a deficient number, since it is larger than the sum of its proper divisors (1).

77477878249 is an equidigital number, since it uses as much as digits as its factorization.

77477878249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 309786624, while the sum is 70.

The spelling of 77477878249 in words is "seventy-seven billion, four hundred seventy-seven million, eight hundred seventy-eight thousand, two hundred forty-nine".