667890 has 48 divisors (see below), whose sum is σ = 1788696. Its totient is φ = 172800.

The previous prime is 667883. The next prime is 667903. The reversal of 667890 is 98766.

It can be written as a sum of positive squares in 4 ways, for example, as 145161 + 522729 = 381^2 + 723^2 .

It is a Curzon number.

It is an unprimeable number.

667890 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 23 ways as a sum of consecutive naturals, for example, 3600 + ... + 3780.

2⁶⁶⁷⁸⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (894348).

667890 is an abundant number, since it is smaller than the sum of its proper divisors (1120806).

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

667890 is a wasteful number, since it uses less digits than its factorization.

667890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 667890 is about 817.2453731897. The cubic root of 667890 is about 87.4114478282.

It can be divided in two parts, 6 and 67890, that added together give a triangular number (67896 = T₃₆₈).

The spelling of 667890 in words is "six hundred sixty-seven thousand, eight hundred ninety".