77787313 has 2 divisors, whose sum is σ = 77787314. Its totient is φ = 77787312.

The previous prime is 77787293. The next prime is 77787331. The reversal of 77787313 is 31378777.

Together with next prime (77787331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 46348864 + 31438449 = 6808^2 + 5607^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77787313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77787313.

It is not a weakly prime, because it can be changed into another prime (77787013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38893656 + 38893657.

It is an arithmetic number, because the mean of its divisors is an integer number (38893657).

Almost surely, 2^77787313 is an apocalyptic number.

It is an amenable number.

77787313 is a deficient number, since it is larger than the sum of its proper divisors (1).

77787313 is an equidigital number, since it uses as much as digits as its factorization.

77787313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172872, while the sum is 43.

The square root of 77787313 is about 8819.7116166006. The cubic root of 77787313 is about 426.8771646739.

The spelling of 77787313 in words is "seventy-seven million, seven hundred eighty-seven thousand, three hundred thirteen".