678400031 has 2 divisors, whose sum is σ = 678400032. Its totient is φ = 678400030.

The previous prime is 678400027. The next prime is 678400033. The reversal of 678400031 is 130004876.

678400031 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 678400031 - 2² = 678400027 is a prime.

It is a super-2 number, since 2×678400031² = 920453204121601922, which contains 22 as substring.

Together with 678400033, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 678399967 and 678400003.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678400033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339200015 + 339200016.

It is an arithmetic number, because the mean of its divisors is an integer number (339200016).

Almost surely, 2^678400031 is an apocalyptic number.

678400031 is a deficient number, since it is larger than the sum of its proper divisors (1).

678400031 is an equidigital number, since it uses as much as digits as its factorization.

678400031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 678400031 is about 26046.1135488579. The cubic root of 678400031 is about 878.6757073950.

The spelling of 678400031 in words is "six hundred seventy-eight million, four hundred thousand, thirty-one".