664635331120 has 20 divisors (see below), whose sum is σ = 1545277145040. Its totient is φ = 265854132416.

The previous prime is 664635331037. The next prime is 664635331123. The reversal of 664635331120 is 21133536466.

664635331120 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (664635331123) 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, 4153970740 + ... + 4153970899.

It is an arithmetic number, because the mean of its divisors is an integer number (77263857252).

Almost surely, 2^664635331120 is an apocalyptic number.

It is an amenable number.

664635331120 is an abundant number, since it is smaller than the sum of its proper divisors (880641813920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664635331120 is a wasteful number, since it uses less digits than its factorization.

664635331120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8307941652 (or 8307941646 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 40.

Adding to 664635331120 its reverse (21133536466), we get a palindrome (685768867586).

The spelling of 664635331120 in words is "six hundred sixty-four billion, six hundred thirty-five million, three hundred thirty-one thousand, one hundred twenty".