55117920 has 288 divisors, whose sum is σ = 208335456. Its totient is φ = 12165120.

The previous prime is 55117891. The next prime is 55117943. The reversal of 55117920 is 2971155.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 755004 + ... + 755076.

It is an arithmetic number, because the mean of its divisors is an integer number (723387).

Almost surely, 2^55117920 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 55117920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104167728).

55117920 is an abundant number, since it is smaller than the sum of its proper divisors (153217536).

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

55117920 is a wasteful number, since it uses less digits than its factorization.

55117920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 3150, while the sum is 30.

The square root of 55117920 is about 7424.1443951475. The cubic root of 55117920 is about 380.5668364078.

It can be divided in two parts, 5511 and 7920, that added together give a palindrome (13431).

The spelling of 55117920 in words is "fifty-five million, one hundred seventeen thousand, nine hundred twenty".