664418873 has 2 divisors, whose sum is σ = 664418874. Its totient is φ = 664418872.

The previous prime is 664418861. The next prime is 664418897. The reversal of 664418873 is 378814466.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 541585984 + 122832889 = 23272^2 + 11083^2 .

It is a cyclic number.

It is not a de Polignac number, because 664418873 - 2⁴ = 664418857 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (664414873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332209436 + 332209437.

It is an arithmetic number, because the mean of its divisors is an integer number (332209437).

Almost surely, 2^664418873 is an apocalyptic number.

It is an amenable number.

664418873 is a deficient number, since it is larger than the sum of its proper divisors (1).

664418873 is an equidigital number, since it uses as much as digits as its factorization.

664418873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 774144, while the sum is 47.

The square root of 664418873 is about 25776.3238845263. The cubic root of 664418873 is about 872.5975448887.

The spelling of 664418873 in words is "six hundred sixty-four million, four hundred eighteen thousand, eight hundred seventy-three".