55221357312 has 864 divisors, whose sum is σ = 196705926144. Its totient is φ = 15261696000.

The previous prime is 55221357311. The next prime is 55221357319. The reversal of 55221357312 is 21375312255.

55221357312 is a `hidden beast` number, since 5 + 52 + 21 + 3 + 573 + 12 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55221357311) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 546746062 + ... + 546746162.

It is an arithmetic number, because the mean of its divisors is an integer number (227668896).

Almost surely, 2^55221357312 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 55221357312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98352963072).

55221357312 is an abundant number, since it is smaller than the sum of its proper divisors (141484568832).

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

55221357312 is a wasteful number, since it uses less digits than its factorization.

55221357312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 181 counting only the distinct ones).

The product of its digits is 63000, while the sum is 36.

Adding to 55221357312 its reverse (21375312255), we get a palindrome (76596669567).

The spelling of 55221357312 in words is "fifty-five billion, two hundred twenty-one million, three hundred fifty-seven thousand, three hundred twelve".