55187915838 has 64 divisors (see below), whose sum is σ = 122770805760. Its totient is φ = 16535492160.

The previous prime is 55187915833. The next prime is 55187915891. The reversal of 55187915838 is 83851978155.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55187915833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 671931 + ... + 749577.

It is an arithmetic number, because the mean of its divisors is an integer number (1918293840).

Almost surely, 2^55187915838 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55187915838, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61385402880).

55187915838 is an abundant number, since it is smaller than the sum of its proper divisors (67582889922).

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

55187915838 is a wasteful number, since it uses less digits than its factorization.

55187915838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77774 (or 77752 counting only the distinct ones).

The product of its digits is 12096000, while the sum is 60.

The spelling of 55187915838 in words is "fifty-five billion, one hundred eighty-seven million, nine hundred fifteen thousand, eight hundred thirty-eight".