78544087121 has 4 divisors (see below), whose sum is σ = 79239167652. Its totient is φ = 77849006592.

The previous prime is 78544087103. The next prime is 78544087151. The reversal of 78544087121 is 12178044587.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14747430721 + 63796656400 = 121439^2 + 252580^2 .

It is a cyclic number.

It is not a de Polignac number, because 78544087121 - 2⁶ = 78544087057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78544087151) 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, 347540096 + ... + 347540321.

It is an arithmetic number, because the mean of its divisors is an integer number (19809791913).

Almost surely, 2^78544087121 is an apocalyptic number.

It is an amenable number.

78544087121 is a deficient number, since it is larger than the sum of its proper divisors (695080531).

78544087121 is a wasteful number, since it uses less digits than its factorization.

78544087121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695080530.

The product of its (nonzero) digits is 501760, while the sum is 47.

The spelling of 78544087121 in words is "seventy-eight billion, five hundred forty-four million, eighty-seven thousand, one hundred twenty-one".