55643477820 has 288 divisors, whose sum is σ = 186504933888. Its totient is φ = 12353822208.

The previous prime is 55643477759. The next prime is 55643477833. The reversal of 55643477820 is 2877434655.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 16047727 + ... + 16051193.

It is an arithmetic number, because the mean of its divisors is an integer number (647586576).

Almost surely, 2^55643477820 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 55643477820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93252466944).

55643477820 is an abundant number, since it is smaller than the sum of its proper divisors (130861456068).

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

55643477820 is a wasteful number, since it uses less digits than its factorization.

55643477820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3649 (or 3640 counting only the distinct ones).

The product of its (nonzero) digits is 5644800, while the sum is 51.

The spelling of 55643477820 in words is "fifty-five billion, six hundred forty-three million, four hundred seventy-seven thousand, eight hundred twenty".