666419 has 4 divisors (see below), whose sum is σ = 717696. Its totient is φ = 615144.

The previous prime is 666403. The next prime is 666427. The reversal of 666419 is 914666.

666419 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 914666 = 2 ⋅457333.

It is a cyclic number.

It is not a de Polignac number, because 666419 - 2⁴ = 666403 is a prime.

It is a super-2 number, since 2×666419² = 888228567122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666439) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25619 + ... + 25644.

It is an arithmetic number, because the mean of its divisors is an integer number (179424).

2⁶⁶⁶⁴¹⁹ is an apocalyptic number.

666419 is a deficient number, since it is larger than the sum of its proper divisors (51277).

666419 is a wasteful number, since it uses less digits than its factorization.

666419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51276.

The product of its digits is 7776, while the sum is 32.

The square root of 666419 is about 816.3449025994. The cubic root of 666419 is about 87.3472272957.

The spelling of 666419 in words is "six hundred sixty-six thousand, four hundred nineteen".