656242135220 has 192 divisors, whose sum is σ = 1602311155200. Its totient is φ = 221140592640.

The previous prime is 656242135207. The next prime is 656242135261. The reversal of 656242135220 is 22531242656.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 992801690 + ... + 992802350.

It is an arithmetic number, because the mean of its divisors is an integer number (8345370600).

Almost surely, 2^656242135220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656242135220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (801155577600).

656242135220 is an abundant number, since it is smaller than the sum of its proper divisors (946069019980).

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

656242135220 is a wasteful number, since it uses less digits than its factorization.

656242135220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1258 (or 1256 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 38.

Adding to 656242135220 its reverse (22531242656), we get a palindrome (678773377876).

The spelling of 656242135220 in words is "six hundred fifty-six billion, two hundred forty-two million, one hundred thirty-five thousand, two hundred twenty".