78298315891 has 4 divisors (see below), whose sum is σ = 78485185800. Its totient is φ = 78111445984.

The previous prime is 78298315877. The next prime is 78298315903. The reversal of 78298315891 is 19851389287.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19851389287 = 63299 ⋅313613.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78298315891 is a prime.

It is a super-2 number, since 2×78298315891² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78298315801) 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, 93434326 + ... + 93435163.

It is an arithmetic number, because the mean of its divisors is an integer number (19621296450).

Almost surely, 2^78298315891 is an apocalyptic number.

78298315891 is a deficient number, since it is larger than the sum of its proper divisors (186869909).

78298315891 is a wasteful number, since it uses less digits than its factorization.

78298315891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186869908.

The product of its digits is 8709120, while the sum is 61.

The spelling of 78298315891 in words is "seventy-eight billion, two hundred ninety-eight million, three hundred fifteen thousand, eight hundred ninety-one".