55687721137536 has 128 divisors (see below), whose sum is σ = 156783700085760. Its totient is φ = 17452588769280.

The previous prime is 55687721137511. The next prime is 55687721137537. The reversal of 55687721137536 is 63573112778655.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×55687721137536² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55687721137537) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1901721 + ... + 10723431.

It is an arithmetic number, because the mean of its divisors is an integer number (1224872656920).

Almost surely, 2^{55687721137536} 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 55687721137536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78391850042880).

55687721137536 is an abundant number, since it is smaller than the sum of its proper divisors (101095978948224).

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

55687721137536 is a wasteful number, since it uses less digits than its factorization.

55687721137536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8822712 (or 8822700 counting only the distinct ones).

The product of its digits is 222264000, while the sum is 66.

The spelling of 55687721137536 in words is "fifty-five trillion, six hundred eighty-seven billion, seven hundred twenty-one million, one hundred thirty-seven thousand, five hundred thirty-six".