664376429 has 4 divisors (see below), whose sum is σ = 668608284. Its totient is φ = 660144576.

The previous prime is 664376417. The next prime is 664376441. The reversal of 664376429 is 924673466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 924673466 = 2 ⋅462336733.

It is an interprime number because it is at equal distance from previous prime (664376417) and next prime (664376441).

It can be written as a sum of positive squares in 2 ways, for example, as 93644329 + 570732100 = 9677^2 + 23890^2 .

It is a cyclic number.

It is not a de Polignac number, because 664376429 - 2²⁰ = 663327853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664376129) 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, 2115692 + ... + 2116005.

It is an arithmetic number, because the mean of its divisors is an integer number (167152071).

Almost surely, 2^664376429 is an apocalyptic number.

It is an amenable number.

664376429 is a deficient number, since it is larger than the sum of its proper divisors (4231855).

664376429 is a wasteful number, since it uses less digits than its factorization.

664376429 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4231854.

The product of its digits is 1306368, while the sum is 47.

The square root of 664376429 is about 25775.5005577001. The cubic root of 664376429 is about 872.5789635788.

The spelling of 664376429 in words is "six hundred sixty-four million, three hundred seventy-six thousand, four hundred twenty-nine".