55720280 has 128 divisors (see below), whose sum is σ = 158976000. Its totient is φ = 17072640.

The previous prime is 55720279. The next prime is 55720289. The reversal of 55720280 is 8202755.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55720289) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 243206 + ... + 243434.

It is an arithmetic number, because the mean of its divisors is an integer number (1242000).

Almost surely, 2^55720280 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 55720280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79488000).

55720280 is an abundant number, since it is smaller than the sum of its proper divisors (103255720).

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

55720280 is a wasteful number, since it uses less digits than its factorization.

55720280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 29.

The square root of 55720280 is about 7464.6017978188. The cubic root of 55720280 is about 381.9481669024.

The spelling of 55720280 in words is "fifty-five million, seven hundred twenty thousand, two hundred eighty".