55778879520 has 1440 divisors, whose sum is σ = 256673197872. Its totient is φ = 10924720128.

The previous prime is 55778879509. The next prime is 55778879549. The reversal of 55778879520 is 2597887755.

55778879520 is a `hidden beast` number, since 5 + 577 + 8 + 8 + 7 + 9 + 52 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 23192853264 + 32586026256 = 152292^2 + 180516^2 .

It is a tau number, because it is divible by the number of its divisors (1440).

It is a super-2 number, since 2×55778879520² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 764094204 + ... + 764094276.

Almost surely, 2^55778879520 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 55778879520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128336598936).

55778879520 is an abundant number, since it is smaller than the sum of its proper divisors (200894318352).

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

55778879520 is a wasteful number, since it uses less digits than its factorization.

55778879520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 49392000, while the sum is 63.

The spelling of 55778879520 in words is "fifty-five billion, seven hundred seventy-eight million, eight hundred seventy-nine thousand, five hundred twenty".