78618783517 has 4 divisors (see below), whose sum is σ = 82036991520. Its totient is φ = 75200575516.

The previous prime is 78618783479. The next prime is 78618783527. The reversal of 78618783517 is 71538781687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71538781687 = 33391 ⋅2142457.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78618783517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78618783527) 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 3 ways as a sum of consecutive naturals, for example, 1709103967 + ... + 1709104012.

It is an arithmetic number, because the mean of its divisors is an integer number (20509247880).

Almost surely, 2^78618783517 is an apocalyptic number.

It is an amenable number.

78618783517 is a deficient number, since it is larger than the sum of its proper divisors (3418208003).

78618783517 is a wasteful number, since it uses less digits than its factorization.

78618783517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3418208002.

The product of its digits is 15805440, while the sum is 61.

The spelling of 78618783517 in words is "seventy-eight billion, six hundred eighteen million, seven hundred eighty-three thousand, five hundred seventeen".