666165958 has 4 divisors (see below), whose sum is σ = 999248940. Its totient is φ = 333082978.

The previous prime is 666165947. The next prime is 666165971. The reversal of 666165958 is 859561666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166541488 + ... + 166541491.

It is an arithmetic number, because the mean of its divisors is an integer number (249812235).

Almost surely, 2^666165958 is an apocalyptic number.

666165958 is a deficient number, since it is larger than the sum of its proper divisors (333082982).

666165958 is a wasteful number, since it uses less digits than its factorization.

666165958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333082981.

The product of its digits is 2332800, while the sum is 52.

The square root of 666165958 is about 25810.1909717848. The cubic root of 666165958 is about 873.3617053049.

The spelling of 666165958 in words is "six hundred sixty-six million, one hundred sixty-five thousand, nine hundred fifty-eight".