61568555220 has 432 divisors, whose sum is σ = 202362451200. Its totient is φ = 15722885376.

The previous prime is 61568555177. The next prime is 61568555231. The reversal of 61568555220 is 2255586516.

61568555220 is a `hidden beast` number, since 6 + 15 + 6 + 85 + 552 + 2 + 0 = 666.

61568555220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 413211706 + ... + 413211854.

It is an arithmetic number, because the mean of its divisors is an integer number (468431600).

Almost surely, 2^61568555220 is an apocalyptic number.

61568555220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61568555220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101181225600).

61568555220 is an abundant number, since it is smaller than the sum of its proper divisors (140793895980).

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

61568555220 is a wasteful number, since it uses less digits than its factorization.

61568555220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 45.

The spelling of 61568555220 in words is "sixty-one billion, five hundred sixty-eight million, five hundred fifty-five thousand, two hundred twenty".