55209280 has 112 divisors (see below), whose sum is σ = 153619200. Its totient is φ = 18891264.

The previous prime is 55209277. The next prime is 55209289. The reversal of 55209280 is 8290255.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55209289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 109509 + ... + 110011.

It is an arithmetic number, because the mean of its divisors is an integer number (1371600).

Almost surely, 2^55209280 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 55209280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76809600).

55209280 is an abundant number, since it is smaller than the sum of its proper divisors (98409920).

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

55209280 is an equidigital number, since it uses as much as digits as its factorization.

55209280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 31.

The square root of 55209280 is about 7430.2947451632. The cubic root of 55209280 is about 380.7769882288.

The spelling of 55209280 in words is "fifty-five million, two hundred nine thousand, two hundred eighty".