78977 has 2 divisors, whose sum is σ = 78978. Its totient is φ = 78976.

The previous prime is 78941. The next prime is 78979. The reversal of 78977 is 77987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78961 + 16 = 281^2 + 4^2 .

It is a cyclic number.

It is not a de Polignac number, because 78977 - 2⁸ = 78721 is a prime.

Together with 78979, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78977.

It is not a weakly prime, because it can be changed into another prime (78979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39488 + 39489.

It is an arithmetic number, because the mean of its divisors is an integer number (39489).

2⁷⁸⁹⁷⁷ is an apocalyptic number.

It is an amenable number.

78977 is a deficient number, since it is larger than the sum of its proper divisors (1).

78977 is an equidigital number, since it uses as much as digits as its factorization.

78977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24696, while the sum is 38.

The square root of 78977 is about 281.0284683088. The cubic root of 78977 is about 42.9042397593.

Subtracting from 78977 its reverse (77987), we obtain a triangular number (990 = T₄₄).

The spelling of 78977 in words is "seventy-eight thousand, nine hundred seventy-seven".