78077 has 4 divisors (see below), whose sum is σ = 78720. Its totient is φ = 77436.

The previous prime is 78059. The next prime is 78079. The reversal of 78077 is 77087.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 77087 = 157 ⋅491.

It is a cyclic number.

It is not a de Polignac number, because 78077 - 2¹⁶ = 12541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78079) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77 + ... + 402.

It is an arithmetic number, because the mean of its divisors is an integer number (19680).

2⁷⁸⁰⁷⁷ is an apocalyptic number.

It is an amenable number.

78077 is a deficient number, since it is larger than the sum of its proper divisors (643).

78077 is a wasteful number, since it uses less digits than its factorization.

78077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642.

The product of its (nonzero) digits is 2744, while the sum is 29.

The square root of 78077 is about 279.4226189842. The cubic root of 78077 is about 42.7406417964.

Subtracting from 78077 its reverse (77087), we obtain a triangular number (990 = T₄₄).

The spelling of 78077 in words is "seventy-eight thousand, seventy-seven".