78255867681 has 24 divisors (see below), whose sum is σ = 114451638600. Its totient is φ = 51521273856.

The previous prime is 78255867673. The next prime is 78255867689. The reversal of 78255867681 is 18676855287.

78255867681 is a `hidden beast` number, since 7 + 8 + 2 + 558 + 6 + 76 + 8 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (78255867673) and next prime (78255867689).

It can be written as a sum of positive squares in 4 ways, for example, as 9236171025 + 69019696656 = 96105^2 + 262716^2 .

It is not a de Polignac number, because 78255867681 - 2³ = 78255867673 is a prime.

It is a super-2 number, since 2×78255867681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78255867689) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73545 + ... + 402393.

It is an arithmetic number, because the mean of its divisors is an integer number (4768818275).

Almost surely, 2^78255867681 is an apocalyptic number.

It is an amenable number.

78255867681 is a deficient number, since it is larger than the sum of its proper divisors (36195770919).

78255867681 is a wasteful number, since it uses less digits than its factorization.

78255867681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329185 (or 329182 counting only the distinct ones).

The product of its digits is 45158400, while the sum is 63.

The spelling of 78255867681 in words is "seventy-eight billion, two hundred fifty-five million, eight hundred sixty-seven thousand, six hundred eighty-one".