666416 has 10 divisors (see below), whose sum is σ = 1291212. Its totient is φ = 333200.

The previous prime is 666403. The next prime is 666427. The reversal of 666416 is 614666.

It is a super-2 number, since 2×666416² = 888220570112, which contains 22 as substring.

It is an unprimeable number.

666416 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20810 + ... + 20841.

2⁶⁶⁶⁴¹⁶ is an apocalyptic number.

It is an amenable number.

666416 is a deficient number, since it is larger than the sum of its proper divisors (624796).

666416 is a wasteful number, since it uses less digits than its factorization.

666416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41659 (or 41653 counting only the distinct ones).

The product of its digits is 5184, while the sum is 29.

The square root of 666416 is about 816.3430651387. The cubic root of 666416 is about 87.3470962259.

The spelling of 666416 in words is "six hundred sixty-six thousand, four hundred sixteen".