55278798138 has 192 divisors, whose sum is σ = 133597900800. Its totient is φ = 17090948160.

The previous prime is 55278798077. The next prime is 55278798143. The reversal of 55278798138 is 83189787255.

55278798138 is a `hidden beast` number, since 5 + 527 + 8 + 7 + 98 + 13 + 8 = 666.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 52100128 + ... + 52101188.

It is an arithmetic number, because the mean of its divisors is an integer number (695822400).

Almost surely, 2^55278798138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55278798138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66798950400).

55278798138 is an abundant number, since it is smaller than the sum of its proper divisors (78319102662).

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

55278798138 is a wasteful number, since it uses less digits than its factorization.

55278798138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1239 (or 1227 counting only the distinct ones).

The product of its digits is 33868800, while the sum is 63.

The spelling of 55278798138 in words is "fifty-five billion, two hundred seventy-eight million, seven hundred ninety-eight thousand, one hundred thirty-eight".