678807352081 has 2 divisors, whose sum is σ = 678807352082. Its totient is φ = 678807352080.

The previous prime is 678807352073. The next prime is 678807352127. The reversal of 678807352081 is 180253708876.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 464600371456 + 214206980625 = 681616^2 + 462825^2 .

It is a cyclic number.

It is not a de Polignac number, because 678807352081 - 2³ = 678807352073 is a prime.

It is a super-2 number, since 2×678807352081² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (678807352021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339403676040 + 339403676041.

It is an arithmetic number, because the mean of its divisors is an integer number (339403676041).

Almost surely, 2^678807352081 is an apocalyptic number.

It is an amenable number.

678807352081 is a deficient number, since it is larger than the sum of its proper divisors (1).

678807352081 is an equidigital number, since it uses as much as digits as its factorization.

678807352081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4515840, while the sum is 55.

The spelling of 678807352081 in words is "six hundred seventy-eight billion, eight hundred seven million, three hundred fifty-two thousand, eighty-one".