78526507009 has 2 divisors, whose sum is σ = 78526507010. Its totient is φ = 78526507008.

The previous prime is 78526507001. The next prime is 78526507021. The reversal of 78526507009 is 90070562587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 61319626384 + 17206880625 = 247628^2 + 131175^2 .

It is an emirp because it is prime and its reverse (90070562587) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78526507009 - 2³ = 78526507001 is a prime.

It is a super-2 number, since 2×78526507009² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78526507001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39263253504 + 39263253505.

It is an arithmetic number, because the mean of its divisors is an integer number (39263253505).

Almost surely, 2^78526507009 is an apocalyptic number.

It is an amenable number.

78526507009 is a deficient number, since it is larger than the sum of its proper divisors (1).

78526507009 is an equidigital number, since it uses as much as digits as its factorization.

78526507009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1058400, while the sum is 49.

The spelling of 78526507009 in words is "seventy-eight billion, five hundred twenty-six million, five hundred seven thousand, nine".