78889521121 has 4 divisors (see below), whose sum is σ = 83041601200. Its totient is φ = 74737441044.

The previous prime is 78889521097. The next prime is 78889521127. The reversal of 78889521121 is 12112598887.

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 an emirpimes, since its reverse is a distinct semiprime: 12112598887 = 313 ⋅38698399.

It is a cyclic number.

It is not a de Polignac number, because 78889521121 - 2²¹ = 78887423969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78889521127) 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, 2076040011 + ... + 2076040048.

It is an arithmetic number, because the mean of its divisors is an integer number (20760400300).

Almost surely, 2^78889521121 is an apocalyptic number.

It is an amenable number.

78889521121 is a deficient number, since it is larger than the sum of its proper divisors (4152080079).

78889521121 is a wasteful number, since it uses less digits than its factorization.

78889521121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4152080078.

The product of its digits is 645120, while the sum is 52.

The spelling of 78889521121 in words is "seventy-eight billion, eight hundred eighty-nine million, five hundred twenty-one thousand, one hundred twenty-one".