55505550 has 96 divisors (see below), whose sum is σ = 144356832. Its totient is φ = 14100480.

The previous prime is 55505539. The next prime is 55505557. The reversal of 55505550 is 5550555.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55505557) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 405082 + ... + 405218.

It is an arithmetic number, because the mean of its divisors is an integer number (1503717).

Almost surely, 2^55505550 is an apocalyptic number.

55505550 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 55505550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72178416).

55505550 is an abundant number, since it is smaller than the sum of its proper divisors (88851282).

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

55505550 is a wasteful number, since it uses less digits than its factorization.

55505550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262 (or 257 counting only the distinct ones).

The product of its (nonzero) digits is 15625, while the sum is 30.

The square root of 55505550 is about 7450.2046951745. The cubic root of 55505550 is about 381.4568956749.

The spelling of 55505550 in words is "fifty-five million, five hundred five thousand, five hundred fifty".