77778985 has 8 divisors (see below), whose sum is σ = 97392960. Its totient is φ = 59517744.

The previous prime is 77778983. The next prime is 77779001. The reversal of 77778985 is 58987777.

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

It is not a de Polignac number, because 77778985 - 2¹ = 77778983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77778983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338055 + ... + 338284.

It is an arithmetic number, because the mean of its divisors is an integer number (12174120).

Almost surely, 2^77778985 is an apocalyptic number.

It is an amenable number.

77778985 is a deficient number, since it is larger than the sum of its proper divisors (19613975).

77778985 is a wasteful number, since it uses less digits than its factorization.

77778985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676367.

The product of its digits is 6914880, while the sum is 58.

The square root of 77778985 is about 8819.2394796830. The cubic root of 77778985 is about 426.8619301420.

The spelling of 77778985 in words is "seventy-seven million, seven hundred seventy-eight thousand, nine hundred eighty-five".