664236805 has 8 divisors (see below), whose sum is σ = 797672952. Its totient is φ = 530996928.

The previous prime is 664236779. The next prime is 664236817. The reversal of 664236805 is 508632466.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 490445316 + 173791489 = 22146^2 + 13183^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 664236805 - 2¹³ = 664228613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41514 + ... + 55243.

It is an arithmetic number, because the mean of its divisors is an integer number (99709119).

Almost surely, 2^664236805 is an apocalyptic number.

It is an amenable number.

664236805 is a deficient number, since it is larger than the sum of its proper divisors (133436147).

664236805 is a wasteful number, since it uses less digits than its factorization.

664236805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98135.

The product of its (nonzero) digits is 207360, while the sum is 40.

The square root of 664236805 is about 25772.7919519791. The cubic root of 664236805 is about 872.5178328224.

The spelling of 664236805 in words is "six hundred sixty-four million, two hundred thirty-six thousand, eight hundred five".