78477877109 has 2 divisors, whose sum is σ = 78477877110. Its totient is φ = 78477877108.

The previous prime is 78477877091. The next prime is 78477877117. The reversal of 78477877109 is 90177877487.

Together with previous prime (78477877091) 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., 63076322500 + 15401554609 = 251150^2 + 124103^2 .

It is a cyclic number.

It is not a de Polignac number, because 78477877109 - 2⁸ = 78477876853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78477877409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39238938554 + 39238938555.

It is an arithmetic number, because the mean of its divisors is an integer number (39238938555).

Almost surely, 2^78477877109 is an apocalyptic number.

It is an amenable number.

78477877109 is a deficient number, since it is larger than the sum of its proper divisors (1).

78477877109 is an equidigital number, since it uses as much as digits as its factorization.

78477877109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38723328, while the sum is 65.

The spelling of 78477877109 in words is "seventy-eight billion, four hundred seventy-seven million, eight hundred seventy-seven thousand, one hundred nine".