55021830 has 32 divisors (see below), whose sum is σ = 132645600. Its totient is φ = 14606592.

The previous prime is 55021829. The next prime is 55021867. The reversal of 55021830 is 3812055.

It is a self number, because there is not a number n which added to its sum of digits gives 55021830.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2866 + ... + 10874.

It is an arithmetic number, because the mean of its divisors is an integer number (4145175).

Almost surely, 2^55021830 is an apocalyptic number.

55021830 is an abundant number, since it is smaller than the sum of its proper divisors (77623770).

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

55021830 is a wasteful number, since it uses less digits than its factorization.

55021830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8248.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 55021830 is about 7417.6701193838. The cubic root of 55021830 is about 380.3455536343.

Adding to 55021830 its reverse (3812055), we get a palindrome (58833885).

The spelling of 55021830 in words is "fifty-five million, twenty-one thousand, eight hundred thirty".