656213216020 has 12 divisors (see below), whose sum is σ = 1378047753684. Its totient is φ = 262485286400.

The previous prime is 656213216011. The next prime is 656213216023. The reversal of 656213216020 is 20612312656.

It can be written as a sum of positive squares in 2 ways, for example, as 145348512516 + 510864703504 = 381246^2 + 714748^2 .

It is a super-2 number, since 2×656213216020² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656213216023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16405330381 + ... + 16405330420.

It is an arithmetic number, because the mean of its divisors is an integer number (114837312807).

Almost surely, 2^656213216020 is an apocalyptic number.

It is an amenable number.

656213216020 is an abundant number, since it is smaller than the sum of its proper divisors (721834537664).

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

656213216020 is a wasteful number, since it uses less digits than its factorization.

656213216020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32810660810 (or 32810660808 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

Adding to 656213216020 its reverse (20612312656), we get a palindrome (676825528676).

The spelling of 656213216020 in words is "six hundred fifty-six billion, two hundred thirteen million, two hundred sixteen thousand, twenty".