78793121 has 4 divisors (see below), whose sum is σ = 85956144. Its totient is φ = 71630100.

The previous prime is 78793109. The next prime is 78793153. The reversal of 78793121 is 12139787.

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: 12139787 = 11 ⋅1103617.

It is a cyclic number.

It is not a de Polignac number, because 78793121 - 2¹⁰ = 78792097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78793321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3581495 + ... + 3581516.

It is an arithmetic number, because the mean of its divisors is an integer number (21489036).

Almost surely, 2^78793121 is an apocalyptic number.

It is an amenable number.

78793121 is a deficient number, since it is larger than the sum of its proper divisors (7163023).

78793121 is a wasteful number, since it uses less digits than its factorization.

78793121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7163022.

The product of its digits is 21168, while the sum is 38.

The square root of 78793121 is about 8876.5489352563. The cubic root of 78793121 is about 428.7091647396.

The spelling of 78793121 in words is "seventy-eight million, seven hundred ninety-three thousand, one hundred twenty-one".