55442240 has 112 divisors (see below), whose sum is σ = 154058112. Its totient is φ = 18610176.

The previous prime is 55442239. The next prime is 55442249. The reversal of 55442240 is 4224455.

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 (55442249) 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, 118487 + ... + 118953.

Almost surely, 2^55442240 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 55442240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77029056).

55442240 is an abundant number, since it is smaller than the sum of its proper divisors (98615872).

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

55442240 is a wasteful number, since it uses less digits than its factorization.

55442240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544 (or 534 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 26.

The square root of 55442240 is about 7445.9546063618. The cubic root of 55442240 is about 381.3118097403.

Adding to 55442240 its reverse (4224455), we get a palindrome (59666695).

The spelling of 55442240 in words is "fifty-five million, four hundred forty-two thousand, two hundred forty".