78294994391 has 4 divisors (see below), whose sum is σ = 78297117192. Its totient is φ = 78292871592.

The previous prime is 78294994361. The next prime is 78294994493. The reversal of 78294994391 is 19349949287.

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

It is a cyclic number.

It is not a de Polignac number, because 78294994391 - 2¹⁰ = 78294993367 is a prime.

It is a super-2 number, since 2×78294994391² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78294994361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1005080 + ... + 1080173.

It is an arithmetic number, because the mean of its divisors is an integer number (19574279298).

Almost surely, 2^78294994391 is an apocalyptic number.

78294994391 is a deficient number, since it is larger than the sum of its proper divisors (2122801).

78294994391 is a wasteful number, since it uses less digits than its factorization.

78294994391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2122800.

The product of its digits is 35271936, while the sum is 65.

The spelling of 78294994391 in words is "seventy-eight billion, two hundred ninety-four million, nine hundred ninety-four thousand, three hundred ninety-one".