78539400077 has 4 divisors (see below), whose sum is σ = 78560055840. Its totient is φ = 78518744316.

The previous prime is 78539400073. The next prime is 78539400131. The reversal of 78539400077 is 77000493587.

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.

It is a cyclic number.

It is not a de Polignac number, because 78539400077 - 2² = 78539400073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78539399998 and 78539400034.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78539400073) 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, 10322177 + ... + 10329782.

It is an arithmetic number, because the mean of its divisors is an integer number (19640013960).

Almost surely, 2^78539400077 is an apocalyptic number.

It is an amenable number.

78539400077 is a deficient number, since it is larger than the sum of its proper divisors (20655763).

78539400077 is a wasteful number, since it uses less digits than its factorization.

78539400077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20655762.

The product of its (nonzero) digits is 1481760, while the sum is 50.

The spelling of 78539400077 in words is "seventy-eight billion, five hundred thirty-nine million, four hundred thousand, seventy-seven".