78213260108777 has 2 divisors, whose sum is σ = 78213260108778. Its totient is φ = 78213260108776.

The previous prime is 78213260108771. The next prime is 78213260108791. The reversal of 78213260108777 is 77780106231287.

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., 51870950218201 + 26342309890576 = 7202149^2 + 5132476^2 .

It is a cyclic number.

It is not a de Polignac number, because 78213260108777 - 2⁴² = 73815213597673 is a prime.

It is a super-2 number, since 2×78213260108777² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78213260108771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39106630054388 + 39106630054389.

It is an arithmetic number, because the mean of its divisors is an integer number (39106630054389).

Almost surely, 2^{78213260108777} is an apocalyptic number.

It is an amenable number.

78213260108777 is a deficient number, since it is larger than the sum of its proper divisors (1).

78213260108777 is an equidigital number, since it uses as much as digits as its factorization.

78213260108777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11063808, while the sum is 59.

The spelling of 78213260108777 in words is "seventy-eight trillion, two hundred thirteen billion, two hundred sixty million, one hundred eight thousand, seven hundred seventy-seven".