78252320513 has 4 divisors (see below), whose sum is σ = 78579736320. Its totient is φ = 77924904708.

The previous prime is 78252320479. The next prime is 78252320519. The reversal of 78252320513 is 31502325287.

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: 31502325287 = 4651 ⋅6773237.

It is a cyclic number.

It is not a de Polignac number, because 78252320513 - 2²⁰ = 78251271937 is a prime.

It is a super-2 number, since 2×78252320513² (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 (78252320519) 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, 163707545 + ... + 163708022.

It is an arithmetic number, because the mean of its divisors is an integer number (19644934080).

Almost surely, 2^78252320513 is an apocalyptic number.

It is an amenable number.

78252320513 is a deficient number, since it is larger than the sum of its proper divisors (327415807).

78252320513 is a wasteful number, since it uses less digits than its factorization.

78252320513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327415806.

The product of its (nonzero) digits is 100800, while the sum is 38.

The spelling of 78252320513 in words is "seventy-eight billion, two hundred fifty-two million, three hundred twenty thousand, five hundred thirteen".