55779786217872 has 240 divisors, whose sum is σ = 162360490406400. Its totient is φ = 17857580544000.

The previous prime is 55779786217861. The next prime is 55779786217879. The reversal of 55779786217872 is 27871268797755.

It is a super-2 number, since 2×55779786217872² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 55779786217791 and 55779786217800.

It is not an unprimeable number, because it can be changed into a prime (55779786217879) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 798793423 + ... + 798863249.

It is an arithmetic number, because the mean of its divisors is an integer number (676502043360).

Almost surely, 2^{55779786217872} 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 55779786217872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81180245203200).

55779786217872 is an abundant number, since it is smaller than the sum of its proper divisors (106580704188528).

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

55779786217872 is a wasteful number, since it uses less digits than its factorization.

55779786217872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71222 (or 71213 counting only the distinct ones).

The product of its digits is 5808499200, while the sum is 81.

The spelling of 55779786217872 in words is "fifty-five trillion, seven hundred seventy-nine billion, seven hundred eighty-six million, two hundred seventeen thousand, eight hundred seventy-two".