55215215120 has 80 divisors (see below), whose sum is σ = 138642970032. Its totient is φ = 20329267200.

The previous prime is 55215215119. The next prime is 55215215129. The reversal of 55215215120 is 2151251255.

It can be written as a sum of positive squares in 8 ways, for example, as 1547006224 + 53668208896 = 39332^2 + 231664^2 .

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

It is a super-2 number, since 2×55215215120² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55215215129) 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, 291920 + ... + 442320.

Almost surely, 2^55215215120 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 55215215120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69321485016).

55215215120 is an abundant number, since it is smaller than the sum of its proper divisors (83427754912).

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

55215215120 is a wasteful number, since it uses less digits than its factorization.

55215215120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150780 (or 150774 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 29.

Adding to 55215215120 its reverse (2151251255), we get a palindrome (57366466375).

The spelling of 55215215120 in words is "fifty-five billion, two hundred fifteen million, two hundred fifteen thousand, one hundred twenty".