667740 has 48 divisors (see below), whose sum is σ = 1935360. Its totient is φ = 171840.

The previous prime is 667727. The next prime is 667741. The reversal of 667740 is 47766.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 667698 and 667707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1681 + ... + 2039.

It is an arithmetic number, because the mean of its divisors is an integer number (40320).

2⁶⁶⁷⁷⁴⁰ is an apocalyptic number.

667740 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (967680).

667740 is an abundant number, since it is smaller than the sum of its proper divisors (1267620).

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

667740 is a wasteful number, since it uses less digits than its factorization.

667740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402 (or 400 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 30.

The square root of 667740 is about 817.1535963330. The cubic root of 667740 is about 87.4049034876.

The spelling of 667740 in words is "six hundred sixty-seven thousand, seven hundred forty".