667749 has 8 divisors (see below), whose sum is σ = 899392. Its totient is φ = 440640.

The previous prime is 667741. The next prime is 667753. The reversal of 667749 is 947766.

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

It is not a de Polignac number, because 667749 - 2³ = 667741 is a prime.

It is a Duffinian number.

667749 is a lucky number.

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 7 ways as a sum of consecutive naturals, for example, 772 + ... + 1389.

It is an arithmetic number, because the mean of its divisors is an integer number (112424).

2⁶⁶⁷⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

667749 is a deficient number, since it is larger than the sum of its proper divisors (231643).

667749 is a wasteful number, since it uses less digits than its factorization.

667749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2267.

The product of its digits is 63504, while the sum is 39.

The square root of 667749 is about 817.1591032351. The cubic root of 667749 is about 87.4052961757.

The spelling of 667749 in words is "six hundred sixty-seven thousand, seven hundred forty-nine".