55785616920 has 224 divisors, whose sum is σ = 205299763920. Its totient is φ = 13523708160.

The previous prime is 55785616907. The next prime is 55785616937. The reversal of 55785616920 is 2961658755.

55785616920 is a `hidden beast` number, since 5 + 5 + 78 + 561 + 6 + 9 + 2 + 0 = 666.

It is a super-2 number, since 2×55785616920² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 233802 + ... + 407718.

Almost surely, 2^55785616920 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 55785616920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102649881960).

55785616920 is an abundant number, since it is smaller than the sum of its proper divisors (149514147000).

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

55785616920 is a wasteful number, since it uses less digits than its factorization.

55785616920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173957 (or 173938 counting only the distinct ones).

The product of its (nonzero) digits is 4536000, while the sum is 54.

The spelling of 55785616920 in words is "fifty-five billion, seven hundred eighty-five million, six hundred sixteen thousand, nine hundred twenty".