664651242620020 has 48 divisors (see below), whose sum is σ = 1414895333261760. Its totient is φ = 262217160320256.

The previous prime is 664651242620009. The next prime is 664651242620077. The reversal of 664651242620020 is 20026242156466.

It is a super-2 number, since 2×664651242620020² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 294383791 + ... + 296632969.

It is an arithmetic number, because the mean of its divisors is an integer number (29476986109620).

Almost surely, 2^{664651242620020} is an apocalyptic number.

It is an amenable number.

664651242620020 is an abundant number, since it is smaller than the sum of its proper divisors (750244090641740).

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

664651242620020 is a wasteful number, since it uses less digits than its factorization.

664651242620020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2451664 (or 2451662 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 46.

Adding to 664651242620020 its reverse (20026242156466), we get a palindrome (684677484776486).

The spelling of 664651242620020 in words is "six hundred sixty-four trillion, six hundred fifty-one billion, two hundred forty-two million, six hundred twenty thousand, twenty".