664820883437 has 4 divisors (see below), whose sum is σ = 664830519936. Its totient is φ = 664811246940.

The previous prime is 664820883407. The next prime is 664820883443. The reversal of 664820883437 is 734388028466.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 734388028466 = 2 ⋅367194014233.

It is a cyclic number.

It is not a de Polignac number, because 664820883437 - 2¹⁰ = 664820882413 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 (664820883407) 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, 4714013 + ... + 4852994.

It is an arithmetic number, because the mean of its divisors is an integer number (166207629984).

Almost surely, 2^664820883437 is an apocalyptic number.

It is an amenable number.

664820883437 is a deficient number, since it is larger than the sum of its proper divisors (9636499).

664820883437 is an equidigital number, since it uses as much as digits as its factorization.

664820883437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9636498.

The product of its (nonzero) digits is 37158912, while the sum is 59.

The spelling of 664820883437 in words is "six hundred sixty-four billion, eight hundred twenty million, eight hundred eighty-three thousand, four hundred thirty-seven".