78342277778 has 18 divisors (see below), whose sum is σ = 120095419143. Its totient is φ = 38328606220.

The previous prime is 78342277771. The next prime is 78342277787. The reversal of 78342277778 is 87777224387.

It can be written as a sum of positive squares in only one way, i.e., 39171138889 + 39171138889 = 197917^2 + 197917^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=197917.

It is a super-2 number, since 2×78342277778² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78342277778.

It is not an unprimeable number, because it can be changed into a prime (78342277771) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 18602093 + ... + 18606303.

Almost surely, 2^78342277778 is an apocalyptic number.

78342277778 is a deficient number, since it is larger than the sum of its proper divisors (41753141365).

78342277778 is an frugal number, since it uses more digits than its factorization.

78342277778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8518 (or 4260 counting only the distinct ones).

The product of its digits is 51631104, while the sum is 62.

The spelling of 78342277778 in words is "seventy-eight billion, three hundred forty-two million, two hundred seventy-seven thousand, seven hundred seventy-eight".