78878077 has 4 divisors (see below), whose sum is σ = 78944956. Its totient is φ = 78811200.

The previous prime is 78878053. The next prime is 78878083. The reversal of 78878077 is 77087887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 77087887 = 29 ⋅2658203.

It can be written as a sum of positive squares in 2 ways, for example, as 3865156 + 75012921 = 1966^2 + 8661^2 .

It is a cyclic number.

It is not a de Polignac number, because 78878077 - 2¹¹ = 78876029 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 (78878027) 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, 31638 + ... + 34039.

It is an arithmetic number, because the mean of its divisors is an integer number (19736239).

Almost surely, 2^78878077 is an apocalyptic number.

It is an amenable number.

78878077 is a deficient number, since it is larger than the sum of its proper divisors (66879).

78878077 is a wasteful number, since it uses less digits than its factorization.

78878077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66878.

The product of its (nonzero) digits is 1229312, while the sum is 52.

The square root of 78878077 is about 8881.3330643547. Note that the first 3 decimals coincide. The cubic root of 78878077 is about 428.8631897489.

The spelling of 78878077 in words is "seventy-eight million, eight hundred seventy-eight thousand, seventy-seven".