664868749 has 16 divisors (see below), whose sum is σ = 699252736. Its totient is φ = 631411200.

The previous prime is 664868747. The next prime is 664868791. The reversal of 664868749 is 947868466.

664868749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 664868749 - 2¹ = 664868747 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 664868693 and 664868702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664868741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 381019 + ... + 382759.

It is an arithmetic number, because the mean of its divisors is an integer number (43703296).

Almost surely, 2^664868749 is an apocalyptic number.

It is an amenable number.

664868749 is a deficient number, since it is larger than the sum of its proper divisors (34383987).

664868749 is a wasteful number, since it uses less digits than its factorization.

664868749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1996.

The product of its digits is 13934592, while the sum is 58.

The square root of 664868749 is about 25785.0489431376. The cubic root of 664868749 is about 872.7944448373.

The spelling of 664868749 in words is "six hundred sixty-four million, eight hundred sixty-eight thousand, seven hundred forty-nine".