664443013 has 8 divisors (see below), whose sum is σ = 720778968. Its totient is φ = 608853504.

The previous prime is 664442957. The next prime is 664443023. The reversal of 664443013 is 310344466.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 165456769 + 498986244 = 12863^2 + 22338^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664443013 is a prime.

It is a super-4 number, since 4×664443013⁴ (a number of 36 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664443023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 184756 + ... + 188317.

It is an arithmetic number, because the mean of its divisors is an integer number (90097371).

Almost surely, 2^664443013 is an apocalyptic number.

It is an amenable number.

664443013 is a deficient number, since it is larger than the sum of its proper divisors (56335955).

664443013 is a wasteful number, since it uses less digits than its factorization.

664443013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373223.

The product of its (nonzero) digits is 20736, while the sum is 31.

The square root of 664443013 is about 25776.7921394420. The cubic root of 664443013 is about 872.6081126447.

Adding to 664443013 its reverse (310344466), we get a palindrome (974787479).

The spelling of 664443013 in words is "six hundred sixty-four million, four hundred forty-three thousand, thirteen".