78172276643 has 4 divisors (see below), whose sum is σ = 79050616920. Its totient is φ = 77293936368.

The previous prime is 78172276607. The next prime is 78172276649. The reversal of 78172276643 is 34667227187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34667227187 = 27197 ⋅1274671.

It is a cyclic number.

It is not a de Polignac number, because 78172276643 - 2⁶ = 78172276579 is a prime.

It is a super-2 number, since 2×78172276643² (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 (78172276649) 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, 439170005 + ... + 439170182.

It is an arithmetic number, because the mean of its divisors is an integer number (19762654230).

Almost surely, 2^78172276643 is an apocalyptic number.

78172276643 is a deficient number, since it is larger than the sum of its proper divisors (878340277).

78172276643 is an equidigital number, since it uses as much as digits as its factorization.

78172276643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878340276.

The product of its digits is 4741632, while the sum is 53.

The spelling of 78172276643 in words is "seventy-eight billion, one hundred seventy-two million, two hundred seventy-six thousand, six hundred forty-three".