665853868 has 6 divisors (see below), whose sum is σ = 1165244276. Its totient is φ = 332926932.

The previous prime is 665853829. The next prime is 665853869. The reversal of 665853868 is 868358566.

It is a super-2 number, since 2×665853868² = 886722747061122848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (665853869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83231730 + ... + 83231737.

Almost surely, 2^665853868 is an apocalyptic number.

It is an amenable number.

665853868 is a deficient number, since it is larger than the sum of its proper divisors (499390408).

665853868 is a wasteful number, since it uses less digits than its factorization.

665853868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166463471 (or 166463469 counting only the distinct ones).

The product of its digits is 8294400, while the sum is 55.

The square root of 665853868 is about 25804.1443958136. The cubic root of 665853868 is about 873.2252978391.

The spelling of 665853868 in words is "six hundred sixty-five million, eight hundred fifty-three thousand, eight hundred sixty-eight".