678631 has 2 divisors, whose sum is σ = 678632. Its totient is φ = 678630.

The previous prime is 678611. The next prime is 678637. The reversal of 678631 is 136876.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 678631 - 2⁵ = 678599 is a prime.

It is a super-2 number, since 2×678631² = 921080068322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 678593 and 678602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (678637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 339315 + 339316.

It is an arithmetic number, because the mean of its divisors is an integer number (339316).

2⁶⁷⁸⁶³¹ is an apocalyptic number.

678631 is a deficient number, since it is larger than the sum of its proper divisors (1).

678631 is an equidigital number, since it uses as much as digits as its factorization.

678631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 678631 is about 823.7906287401. The cubic root of 678631 is about 87.8775414457.

The spelling of 678631 in words is "six hundred seventy-eight thousand, six hundred thirty-one".