55391784 has 64 divisors (see below), whose sum is σ = 161274240. Its totient is φ = 15525120.

The previous prime is 55391773. The next prime is 55391851. The reversal of 55391784 is 48719355.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5794 + ... + 12014.

It is an arithmetic number, because the mean of its divisors is an integer number (2519910).

Almost surely, 2^55391784 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 55391784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80637120).

55391784 is an abundant number, since it is smaller than the sum of its proper divisors (105882456).

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

55391784 is a wasteful number, since it uses less digits than its factorization.

55391784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6290 (or 6286 counting only the distinct ones).

The product of its digits is 151200, while the sum is 42.

The square root of 55391784 is about 7442.5656866433. The cubic root of 55391784 is about 381.1961018853.

The spelling of 55391784 in words is "fifty-five million, three hundred ninety-one thousand, seven hundred eighty-four".