664777985 has 8 divisors (see below), whose sum is σ = 839719680. Its totient is φ = 503831664.

The previous prime is 664777963. The next prime is 664778003. The reversal of 664777985 is 589777466.

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

It is not a de Polignac number, because 664777985 - 2¹⁶ = 664712449 is a prime.

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, 3498737 + ... + 3498926.

It is an arithmetic number, because the mean of its divisors is an integer number (104964960).

Almost surely, 2^664777985 is an apocalyptic number.

It is an amenable number.

664777985 is a deficient number, since it is larger than the sum of its proper divisors (174941695).

664777985 is a wasteful number, since it uses less digits than its factorization.

664777985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6997687.

The product of its digits is 17781120, while the sum is 59.

The square root of 664777985 is about 25783.2888708947. The cubic root of 664777985 is about 872.7547267625.

The spelling of 664777985 in words is "six hundred sixty-four million, seven hundred seventy-seven thousand, nine hundred eighty-five".