664405801 has 2 divisors, whose sum is σ = 664405802. Its totient is φ = 664405800.

The previous prime is 664405741. The next prime is 664405817. The reversal of 664405801 is 108504466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 360810025 + 303595776 = 18995^2 + 17424^2 .

It is a cyclic number.

It is not a de Polignac number, because 664405801 - 2¹³ = 664397609 is a prime.

It is not a weakly prime, because it can be changed into another prime (664405831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332202900 + 332202901.

It is an arithmetic number, because the mean of its divisors is an integer number (332202901).

Almost surely, 2^664405801 is an apocalyptic number.

It is an amenable number.

664405801 is a deficient number, since it is larger than the sum of its proper divisors (1).

664405801 is an equidigital number, since it uses as much as digits as its factorization.

664405801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 664405801 is about 25776.0703172536. The cubic root of 664405801 is about 872.5918222588.

The spelling of 664405801 in words is "six hundred sixty-four million, four hundred five thousand, eight hundred one".