6658 has 4 divisors (see below), whose sum is σ = 9990. Its totient is φ = 3328.

The previous prime is 6653. The next prime is 6659. The reversal of 6658 is 8566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8566 = 2 ⋅4283.

It can be written as a sum of positive squares in only one way, i.e., 5929 + 729 = 77^2 + 27^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1663 + ... + 1666.

2⁶⁶⁵⁸ is an apocalyptic number.

6658 is a deficient number, since it is larger than the sum of its proper divisors (3332).

6658 is a wasteful number, since it uses less digits than its factorization.

6658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3331.

The product of its digits is 1440, while the sum is 25.

The square root of 6658 is about 81.5965685553. The cubic root of 6658 is about 18.8125613954.

It can be divided in two parts, 66 and 58, that multiplied together give a triangular number (3828 = T₈₇).

The spelling of 6658 in words is "six thousand, six hundred fifty-eight".