6691658 has 4 divisors (see below), whose sum is σ = 10037490. Its totient is φ = 3345828.

The previous prime is 6691637. The next prime is 6691661. The reversal of 6691658 is 8561966.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 3892729 + 2798929 = 1973^2 + 1673^2 .

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1672913 + ... + 1672916.

Almost surely, 2^6691658 is an apocalyptic number.

6691658 is a deficient number, since it is larger than the sum of its proper divisors (3345832).

6691658 is a wasteful number, since it uses less digits than its factorization.

6691658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3345831.

The product of its digits is 77760, while the sum is 41.

The square root of 6691658 is about 2586.8239213367. The cubic root of 6691658 is about 188.4420899676.

The spelling of 6691658 in words is "six million, six hundred ninety-one thousand, six hundred fifty-eight".