665458 has 4 divisors (see below), whose sum is σ = 998190. Its totient is φ = 332728.

The previous prime is 665447. The next prime is 665479. The reversal of 665458 is 854566.

665458 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 854566 = 2 ⋅427283.

It can be written as a sum of positive squares in only one way, i.e., 660969 + 4489 = 813^2 + 67^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166363 + ... + 166366.

2⁶⁶⁵⁴⁵⁸ is an apocalyptic number.

665458 is a deficient number, since it is larger than the sum of its proper divisors (332732).

665458 is a wasteful number, since it uses less digits than its factorization.

665458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332731.

The product of its digits is 28800, while the sum is 34.

The square root of 665458 is about 815.7560909978. The cubic root of 665458 is about 87.3052211572.

The spelling of 665458 in words is "six hundred sixty-five thousand, four hundred fifty-eight".