664428204437 has 2 divisors, whose sum is σ = 664428204438. Its totient is φ = 664428204436.

The previous prime is 664428204431. The next prime is 664428204457. The reversal of 664428204437 is 734402824466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 633701970916 + 30726233521 = 796054^2 + 175289^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664428204437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664428204431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332214102218 + 332214102219.

It is an arithmetic number, because the mean of its divisors is an integer number (332214102219).

Almost surely, 2^664428204437 is an apocalyptic number.

It is an amenable number.

664428204437 is a deficient number, since it is larger than the sum of its proper divisors (1).

664428204437 is an equidigital number, since it uses as much as digits as its factorization.

664428204437 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6193152, while the sum is 50.

The spelling of 664428204437 in words is "six hundred sixty-four billion, four hundred twenty-eight million, two hundred four thousand, four hundred thirty-seven".