77868909 has 6 divisors (see below), whose sum is σ = 112477326. Its totient is φ = 51912600.

The previous prime is 77868887. The next prime is 77868911. The reversal of 77868909 is 90986877.

It can be written as a sum of positive squares in only one way, i.e., 66879684 + 10989225 = 8178^2 + 3315^2 .

It is not a de Polignac number, because 77868909 - 2⁵ = 77868877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77868919) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4326042 + ... + 4326059.

It is an arithmetic number, because the mean of its divisors is an integer number (18746221).

Almost surely, 2^77868909 is an apocalyptic number.

It is an amenable number.

77868909 is a deficient number, since it is larger than the sum of its proper divisors (34608417).

77868909 is a wasteful number, since it uses less digits than its factorization.

77868909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8652107 (or 8652104 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 54.

The square root of 77868909 is about 8824.3361789995. The cubic root of 77868909 is about 427.0263719413.

The spelling of 77868909 in words is "seventy-seven million, eight hundred sixty-eight thousand, nine hundred nine".