664587841 has 4 divisors (see below), whose sum is σ = 665380800. Its totient is φ = 663794884.

The previous prime is 664587811. The next prime is 664587853. The reversal of 664587841 is 148785466.

664587841 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is not a de Polignac number, because 664587841 - 2⁷ = 664587713 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664587811) 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, 395221 + ... + 396898.

It is an arithmetic number, because the mean of its divisors is an integer number (166345200).

Almost surely, 2^664587841 is an apocalyptic number.

It is an amenable number.

664587841 is a deficient number, since it is larger than the sum of its proper divisors (792959).

664587841 is an equidigital number, since it uses as much as digits as its factorization.

664587841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 792958.

The product of its digits is 1290240, while the sum is 49.

The square root of 664587841 is about 25779.6012575835. The cubic root of 664587841 is about 872.6715085539.

The spelling of 664587841 in words is "six hundred sixty-four million, five hundred eighty-seven thousand, eight hundred forty-one".