78218906320 has 40 divisors (see below), whose sum is σ = 182326533480. Its totient is φ = 31207119360.

The previous prime is 78218906273. The next prime is 78218906387. The reversal of 78218906320 is 2360981287.

It can be written as a sum of positive squares in 4 ways, for example, as 2596106304 + 75622800016 = 50952^2 + 274996^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×78218906320² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1225611 + ... + 1287850.

It is an arithmetic number, because the mean of its divisors is an integer number (4558163337).

Almost surely, 2^78218906320 is an apocalyptic number.

It is an amenable number.

78218906320 is an abundant number, since it is smaller than the sum of its proper divisors (104107627160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78218906320 is a wasteful number, since it uses less digits than its factorization.

78218906320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2513863 (or 2513857 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 46.

The spelling of 78218906320 in words is "seventy-eight billion, two hundred eighteen million, nine hundred six thousand, three hundred twenty".