55117440 has 192 divisors, whose sum is σ = 217676160. Its totient is φ = 12589056.

The previous prime is 55117397. The next prime is 55117441. The reversal of 55117440 is 4471155.

It is a happy number.

55117440 is a `hidden beast` number, since 551 + 1 + 74 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is not an unprimeable number, because it can be changed into a prime (55117441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39637 + ... + 41003.

It is an arithmetic number, because the mean of its divisors is an integer number (1133730).

Almost surely, 2^55117440 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 55117440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108838080).

55117440 is an abundant number, since it is smaller than the sum of its proper divisors (162558720).

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

55117440 is a wasteful number, since it uses less digits than its factorization.

55117440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1399 (or 1384 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 27.

The square root of 55117440 is about 7424.1120681197. The cubic root of 55117440 is about 380.5657316696.

Adding to 55117440 its reverse (4471155), we get a palindrome (59588595).

The spelling of 55117440 in words is "fifty-five million, one hundred seventeen thousand, four hundred forty".