55821312 has 110 divisors (see below), whose sum is σ = 166941038. Its totient is φ = 18579456.

The previous prime is 55821307. The next prime is 55821323. The reversal of 55821312 is 21312855.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 43877376 + 11943936 = 6624^2 + 3456^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 82608 + ... + 83280.

Almost surely, 2^55821312 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 55821312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83470519).

55821312 is an abundant number, since it is smaller than the sum of its proper divisors (111119726).

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

55821312 is an equidigital number, since it uses as much as digits as its factorization.

55821312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705 (or 678 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 55821312 is about 7471.3661401380. The cubic root of 55821312 is about 382.1788769628.

The spelling of 55821312 in words is "fifty-five million, eight hundred twenty-one thousand, three hundred twelve".