668694 has 16 divisors (see below), whose sum is σ = 1440432. Its totient is φ = 205728.

The previous prime is 668687. The next prime is 668699. The reversal of 668694 is 496866.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668699) by changing a digit.

668694 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4209 + ... + 4364.

It is an arithmetic number, because the mean of its divisors is an integer number (90027).

2⁶⁶⁸⁶⁹⁴ is an apocalyptic number.

668694 is an abundant number, since it is smaller than the sum of its proper divisors (771738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668694 is a wasteful number, since it uses less digits than its factorization.

668694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8591.

The product of its digits is 62208, while the sum is 39.

The square root of 668694 is about 817.7371215739. The cubic root of 668694 is about 87.4465088026.

It can be divided in two parts, 6 and 68694, that multiplied together give a square (412164 = 642²).

The spelling of 668694 in words is "six hundred sixty-eight thousand, six hundred ninety-four".