55139987520 has 448 divisors, whose sum is σ = 202118976000. Its totient is φ = 14134321152.

The previous prime is 55139987501. The next prime is 55139987569. The reversal of 55139987520 is 2578993155.

55139987520 is a `hidden beast` number, since 5 + 5 + 1 + 39 + 9 + 87 + 520 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 89950734 + ... + 89951346.

Almost surely, 2^55139987520 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 55139987520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101059488000).

55139987520 is an abundant number, since it is smaller than the sum of its proper divisors (146978988480).

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

55139987520 is a wasteful number, since it uses less digits than its factorization.

55139987520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1027 (or 1011 counting only the distinct ones).

The product of its (nonzero) digits is 3402000, while the sum is 54.

The spelling of 55139987520 in words is "fifty-five billion, one hundred thirty-nine million, nine hundred eighty-seven thousand, five hundred twenty".