55309644 has 54 divisors (see below), whose sum is σ = 151409076. Its totient is φ = 17016480.

The previous prime is 55309637. The next prime is 55309669. The reversal of 55309644 is 44690355.

It is a happy number.

55309644 is a `hidden beast` number, since 5 + 5 + 3 + 0 + 9 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 55309599 and 55309608.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1539 + ... + 10629.

Almost surely, 2^55309644 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 55309644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75704538).

55309644 is an abundant number, since it is smaller than the sum of its proper divisors (96099432).

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

55309644 is a wasteful number, since it uses less digits than its factorization.

55309644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9127 (or 9109 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 55309644 is about 7437.0453810636. The cubic root of 55309644 is about 381.0075845309.

Adding to 55309644 its reverse (44690355), we get a palindrome (99999999).

The spelling of 55309644 in words is "fifty-five million, three hundred nine thousand, six hundred forty-four".