666469 has 4 divisors (see below), whose sum is σ = 688000. Its totient is φ = 644940.

The previous prime is 666467. The next prime is 666493. The reversal of 666469 is 964666.

666469 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 666469 - 2¹ = 666467 is a prime.

It is a super-2 number, since 2×666469² = 888361855922, 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 (666461) 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, 10719 + ... + 10780.

It is an arithmetic number, because the mean of its divisors is an integer number (172000).

2⁶⁶⁶⁴⁶⁹ is an apocalyptic number.

It is an amenable number.

666469 is a deficient number, since it is larger than the sum of its proper divisors (21531).

666469 is a wasteful number, since it uses less digits than its factorization.

666469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21530.

The product of its digits is 46656, while the sum is 37.

The square root of 666469 is about 816.3755263358. The cubic root of 666469 is about 87.3494117332.

The spelling of 666469 in words is "six hundred sixty-six thousand, four hundred sixty-nine".