55209105920 has 80 divisors (see below), whose sum is σ = 132437023488. Its totient is φ = 22072872960.

The previous prime is 55209105881. The next prime is 55209105929. The reversal of 55209105920 is 2950190255.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (55209105929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7141097 + ... + 7148823.

Almost surely, 2^55209105920 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 55209105920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66218511744).

55209105920 is an abundant number, since it is smaller than the sum of its proper divisors (77227917568).

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

55209105920 is an equidigital number, since it uses as much as digits as its factorization.

55209105920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10541 (or 10525 counting only the distinct ones).

The product of its (nonzero) digits is 40500, while the sum is 38.

The spelling of 55209105920 in words is "fifty-five billion, two hundred nine million, one hundred five thousand, nine hundred twenty".