665954 has 8 divisors (see below), whose sum is σ = 1002540. Its totient is φ = 331776.

The previous prime is 665953. The next prime is 665981. The reversal of 665954 is 459566.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 616225 + 49729 = 785^2 + 223^2 .

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

It is an Ulam number.

It is a plaindrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (665953) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 482 + ... + 1250.

2⁶⁶⁵⁹⁵⁴ is an apocalyptic number.

665954 is a deficient number, since it is larger than the sum of its proper divisors (336586).

665954 is a wasteful number, since it uses less digits than its factorization.

665954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1204.

The product of its digits is 32400, while the sum is 35.

The square root of 665954 is about 816.0600468103. The cubic root of 665954 is about 87.3269067910.

The spelling of 665954 in words is "six hundred sixty-five thousand, nine hundred fifty-four".