55551320 has 64 divisors (see below), whose sum is σ = 137168640. Its totient is φ = 20080000.

The previous prime is 55551289. The next prime is 55551329. The reversal of 55551320 is 2315555.

It is a self number, because there is not a number n which added to its sum of digits gives 55551320.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55551329) 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, 110189 + ... + 110691.

It is an arithmetic number, because the mean of its divisors is an integer number (2143260).

Almost surely, 2^55551320 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 55551320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68584320).

55551320 is an abundant number, since it is smaller than the sum of its proper divisors (81617320).

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

55551320 is a wasteful number, since it uses less digits than its factorization.

55551320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776 (or 772 counting only the distinct ones).

The product of its (nonzero) digits is 3750, while the sum is 26.

The square root of 55551320 is about 7453.2757898792. The cubic root of 55551320 is about 381.5617169365.

Adding to 55551320 its reverse (2315555), we get a palindrome (57866875).

The spelling of 55551320 in words is "fifty-five million, five hundred fifty-one thousand, three hundred twenty".