687978642067 has 2 divisors, whose sum is σ = 687978642068. Its totient is φ = 687978642066.

The previous prime is 687978642053. The next prime is 687978642083. The reversal of 687978642067 is 760246879786.

687978642067 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 687978642067 - 2⁷ = 687978641939 is a prime.

It is a super-2 number, since 2×687978642067² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 687978641987 and 687978642005.

It is not a weakly prime, because it can be changed into another prime (687978642097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343989321033 + 343989321034.

It is an arithmetic number, because the mean of its divisors is an integer number (343989321034).

Almost surely, 2^687978642067 is an apocalyptic number.

687978642067 is a deficient number, since it is larger than the sum of its proper divisors (1).

687978642067 is an equidigital number, since it uses as much as digits as its factorization.

687978642067 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 341397504, while the sum is 70.

The spelling of 687978642067 in words is "six hundred eighty-seven billion, nine hundred seventy-eight million, six hundred forty-two thousand, sixty-seven".