664042469 has 2 divisors, whose sum is σ = 664042470. Its totient is φ = 664042468.

The previous prime is 664042451. The next prime is 664042501. The reversal of 664042469 is 964240466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 406022500 + 258019969 = 20150^2 + 16063^2 .

It is a cyclic number.

It is not a de Polignac number, because 664042469 - 2²⁰ = 662993893 is a prime.

It is a super-3 number, since 3×664042469³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664042409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332021234 + 332021235.

It is an arithmetic number, because the mean of its divisors is an integer number (332021235).

Almost surely, 2^664042469 is an apocalyptic number.

It is an amenable number.

664042469 is a deficient number, since it is larger than the sum of its proper divisors (1).

664042469 is an equidigital number, since it uses as much as digits as its factorization.

664042469 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 41.

The square root of 664042469 is about 25769.0214986910. The cubic root of 664042469 is about 872.4327335711.

The spelling of 664042469 in words is "six hundred sixty-four million, forty-two thousand, four hundred sixty-nine".