55215216 has 240 divisors, whose sum is σ = 197011200. Its totient is φ = 14463360.

The previous prime is 55215179. The next prime is 55215239. The reversal of 55215216 is 61251255.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 55215216.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1781121 + ... + 1781151.

It is an arithmetic number, because the mean of its divisors is an integer number (820880).

Almost surely, 2^55215216 is an apocalyptic number.

55215216 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55215216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98505600).

55215216 is an abundant number, since it is smaller than the sum of its proper divisors (141795984).

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

55215216 is a wasteful number, since it uses less digits than its factorization.

55215216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105 (or 62 counting only the distinct ones).

The product of its digits is 3000, while the sum is 27.

The square root of 55215216 is about 7430.6941802230. The cubic root of 55215216 is about 380.7906345530.

The spelling of 55215216 in words is "fifty-five million, two hundred fifteen thousand, two hundred sixteen".