78212171115 has 96 divisors (see below), whose sum is σ = 147244982976. Its totient is φ = 38176220160.

The previous prime is 78212171113. The next prime is 78212171129. The reversal of 78212171115 is 51117121287.

It is not a de Polignac number, because 78212171115 - 2¹ = 78212171113 is a prime.

It is a super-2 number, since 2×78212171115² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 78212171115.

It is not an unprimeable number, because it can be changed into a prime (78212171113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 80547580 + ... + 80548550.

It is an arithmetic number, because the mean of its divisors is an integer number (1533801906).

Almost surely, 2^78212171115 is an apocalyptic number.

78212171115 is a deficient number, since it is larger than the sum of its proper divisors (69032811861).

78212171115 is a wasteful number, since it uses less digits than its factorization.

78212171115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2029 (or 2026 counting only the distinct ones).

The product of its digits is 7840, while the sum is 36.

The spelling of 78212171115 in words is "seventy-eight billion, two hundred twelve million, one hundred seventy-one thousand, one hundred fifteen".