678975 has 24 divisors (see below), whose sum is σ = 1226112. Its totient is φ = 328800.

The previous prime is 678971. The next prime is 678989. The reversal of 678975 is 579876.

It is a Cunningham number, because it is equal to 824²-1.

It is not a de Polignac number, because 678975 - 2² = 678971 is a prime.

It is a super-2 number, since 2×678975² = 922014101250, which contains 22 as substring.

It is an Ulam number.

678975 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678971) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 414 + ... + 1236.

It is an arithmetic number, because the mean of its divisors is an integer number (51088).

2⁶⁷⁸⁹⁷⁵ is an apocalyptic number.

678975 is a deficient number, since it is larger than the sum of its proper divisors (547137).

678975 is a wasteful number, since it uses less digits than its factorization.

678975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847 (or 842 counting only the distinct ones).

The product of its digits is 105840, while the sum is 42.

The square root of 678975 is about 823.9993932037. Note that the first 3 decimals coincide. The cubic root of 678975 is about 87.8923873968.

Subtracting from 678975 its reverse (579876), we obtain a palindrome (99099).

It can be divided in two parts, 678 and 975, that added together give a triangular number (1653 = T₅₇).

The spelling of 678975 in words is "six hundred seventy-eight thousand, nine hundred seventy-five".