78306256913 has 4 divisors (see below), whose sum is σ = 78306818100. Its totient is φ = 78305695728.

The previous prime is 78306256907. The next prime is 78306256927. The reversal of 78306256913 is 31965260387.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 31965260387 = 85819 ⋅372473.

It can be written as a sum of positive squares in 2 ways, for example, as 23733559249 + 54572697664 = 154057^2 + 233608^2 .

It is a cyclic number.

It is not a de Polignac number, because 78306256913 - 2¹⁰ = 78306255889 is a prime.

It is a super-2 number, since 2×78306256913² (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 (78306256813) 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, 109331 + ... + 410567.

It is an arithmetic number, because the mean of its divisors is an integer number (19576704525).

Almost surely, 2^78306256913 is an apocalyptic number.

It is an amenable number.

78306256913 is a deficient number, since it is larger than the sum of its proper divisors (561187).

78306256913 is a wasteful number, since it uses less digits than its factorization.

78306256913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561186.

The product of its (nonzero) digits is 1632960, while the sum is 50.

The spelling of 78306256913 in words is "seventy-eight billion, three hundred six million, two hundred fifty-six thousand, nine hundred thirteen".