77878609 has 8 divisors (see below), whose sum is σ = 79223040. Its totient is φ = 76545696.

The previous prime is 77878597. The next prime is 77878627. The reversal of 77878609 is 90687877.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77878609 - 2⁷ = 77878481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77878679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11352 + ... + 16870.

It is an arithmetic number, because the mean of its divisors is an integer number (9902880).

Almost surely, 2^77878609 is an apocalyptic number.

It is an amenable number.

77878609 is a deficient number, since it is larger than the sum of its proper divisors (1344431).

77878609 is a wasteful number, since it uses less digits than its factorization.

77878609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5759.

The product of its (nonzero) digits is 1185408, while the sum is 52.

The square root of 77878609 is about 8824.8857782976. The cubic root of 77878609 is about 427.0441025259.

It can be divided in two parts, 77878 and 609, that added together give a palindrome (78487).

The spelling of 77878609 in words is "seventy-seven million, eight hundred seventy-eight thousand, six hundred nine".