678981 has 8 divisors (see below), whose sum is σ = 915840. Its totient is φ = 447392.

The previous prime is 678971. The next prime is 678989. The reversal of 678981 is 189876.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 678981 - 2⁵ = 678949 is a prime.

It is a super-2 number, since 2×678981² = 922030396722, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 678981.

It is not an unprimeable number, because it can be changed into a prime (678989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1005 + ... + 1538.

It is an arithmetic number, because the mean of its divisors is an integer number (114480).

2⁶⁷⁸⁹⁸¹ is an apocalyptic number.

It is an amenable number.

678981 is a deficient number, since it is larger than the sum of its proper divisors (236859).

678981 is a wasteful number, since it uses less digits than its factorization.

678981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2635.

The product of its digits is 24192, while the sum is 39.

The square root of 678981 is about 824.0030339750. The cubic root of 678981 is about 87.8926462933.

It can be divided in two parts, 6 and 78981, that added together give a palindrome (78987).

The spelling of 678981 in words is "six hundred seventy-eight thousand, nine hundred eighty-one".