78186322343809 has 9 divisors (see below), whose sum is σ = 80975636278147. Its totient is φ = 75489994678504.

The previous prime is 78186322343791. The next prime is 78186322343903. The reversal of 78186322343809 is 90834322368187.

The square root of 78186322343809 is 8842303.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 40999010884209 + 37187311459600 = 6403047^2 + 6098140^2 .

It is a de Polignac number, because none of the positive numbers 2^k-78186322343809 is a prime.

It is a super-2 number, since 2×78186322343809² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78186322343309) 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 8 ways as a sum of consecutive naturals, for example, 256274334 + ... + 256579240.

Almost surely, 2^{78186322343809} is an apocalyptic number.

78186322343809 is the 8842303-rd square number.

78186322343809 is the 4421152-nd centered octagonal number.

It is an amenable number.

78186322343809 is a deficient number, since it is larger than the sum of its proper divisors (2789313934338).

78186322343809 is an frugal number, since it uses more digits than its factorization.

78186322343809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609872 (or 304936 counting only the distinct ones).

The product of its (nonzero) digits is 83607552, while the sum is 64.

The spelling of 78186322343809 in words is "seventy-eight trillion, one hundred eighty-six billion, three hundred twenty-two million, three hundred forty-three thousand, eight hundred nine".