656423422464220 has 96 divisors (see below), whose sum is σ = 1421698565726208. Its totient is φ = 254435688283392.

The previous prime is 656423422464191. The next prime is 656423422464449. The reversal of 656423422464220 is 22464224324656.

It is a happy number.

It is a super-2 number, since 2×656423422464220² (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 31 ways as a sum of consecutive naturals, for example, 4399634662 + ... + 4399783858.

It is an arithmetic number, because the mean of its divisors is an integer number (14809360059648).

Almost surely, 2^{656423422464220} 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 656423422464220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (710849282863104).

656423422464220 is an abundant number, since it is smaller than the sum of its proper divisors (765275143261988).

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

656423422464220 is a wasteful number, since it uses less digits than its factorization.

656423422464220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189659 (or 189657 counting only the distinct ones).

The product of its (nonzero) digits is 26542080, while the sum is 52.

Adding to 656423422464220 its reverse (22464224324656), we get a palindrome (678887646788876).

The spelling of 656423422464220 in words is "six hundred fifty-six trillion, four hundred twenty-three billion, four hundred twenty-two million, four hundred sixty-four thousand, two hundred twenty".