664665653 has 2 divisors, whose sum is σ = 664665654. Its totient is φ = 664665652.

The previous prime is 664665649. The next prime is 664665667. The reversal of 664665653 is 356566466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 561073969 + 103591684 = 23687^2 + 10178^2 .

It is a cyclic number.

It is not a de Polignac number, because 664665653 - 2² = 664665649 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 664665598 and 664665607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664665553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332332826 + 332332827.

It is an arithmetic number, because the mean of its divisors is an integer number (332332827).

Almost surely, 2^664665653 is an apocalyptic number.

It is an amenable number.

664665653 is a deficient number, since it is larger than the sum of its proper divisors (1).

664665653 is an equidigital number, since it uses as much as digits as its factorization.

664665653 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2332800, while the sum is 47.

The square root of 664665653 is about 25781.1103911372. The cubic root of 664665653 is about 872.7055655845.

The spelling of 664665653 in words is "six hundred sixty-four million, six hundred sixty-five thousand, six hundred fifty-three".