77978 has 8 divisors (see below), whose sum is σ = 118272.
Its totient is φ = 38556.
The previous prime is 77977. The next prime is 77983. The reversal of 77978 is 87977.
Subtracting 77978 from its reverse (87977), we obtain a palindrome (9999).
It is a sphenic number, since it is the product of 3 distinct primes.
It is not an unprimeable number, because it can be changed into a prime (77977) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101 + ... + 407.
It is an arithmetic number, because the mean of its divisors is an integer number (14784).
277978 is an apocalyptic number.
77978 is a deficient number, since it is larger than the sum of its proper divisors (40294).
77978 is a wasteful number, since it uses less digits than its factorization.
77978 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 436.
The product of its digits is 24696, while the sum is 38.
The square root of 77978 is about 279.2454117797.
The cubic root of 77978 is about 42.7225694097.
The spelling of 77978 in words is "seventy-seven thousand, nine hundred seventy-eight".