78643834687 has 8 divisors (see below), whose sum is σ = 86502310992. Its totient is φ = 71494393960.

The previous prime is 78643834673. The next prime is 78643834721.

78643834687 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 78643834687 - 2¹⁹ = 78643310399 is a prime.

It is a super-4 number, since 4×78643834687⁴ (a number of 45 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78643834627) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29541808 + ... + 29544469.

It is an arithmetic number, because the mean of its divisors is an integer number (10812788874).

Almost surely, 2^78643834687 is an apocalyptic number.

78643834687 is a deficient number, since it is larger than the sum of its proper divisors (7858476305).

78643834687 is an equidigital number, since it uses as much as digits as its factorization.

78643834687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59086310 (or 59086288 counting only the distinct ones).

The product of its digits is 130056192, while the sum is 64.

The spelling of 78643834687 in words is "seventy-eight billion, six hundred forty-three million, eight hundred thirty-four thousand, six hundred eighty-seven".