55724240 has 80 divisors (see below), whose sum is σ = 152240256. Its totient is φ = 18700800.

The previous prime is 55724233. The next prime is 55724243. The reversal of 55724240 is 4242755.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55724243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9005 + ... + 13875.

Almost surely, 2^55724240 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 55724240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76120128).

55724240 is an abundant number, since it is smaller than the sum of its proper divisors (96516016).

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

55724240 is a wasteful number, since it uses less digits than its factorization.

55724240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4908 (or 4902 counting only the distinct ones).

The product of its (nonzero) digits is 11200, while the sum is 29.

The square root of 55724240 is about 7464.8670450317. The cubic root of 55724240 is about 381.9572149481.

Adding to 55724240 its reverse (4242755), we get a palindrome (59966995).

The spelling of 55724240 in words is "fifty-five million, seven hundred twenty-four thousand, two hundred forty".