55784447820 has 96 divisors (see below), whose sum is σ = 177587773440. Its totient is φ = 14529896640.

The previous prime is 55784447813. The next prime is 55784447869. The reversal of 55784447820 is 2874448755.

55784447820 is a `hidden beast` number, since 5 + 578 + 4 + 4 + 47 + 8 + 20 = 666.

It is a super-2 number, since 2×55784447820² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 31 ways as a sum of consecutive naturals, for example, 1177996 + ... + 1224435.

It is an arithmetic number, because the mean of its divisors is an integer number (1849872640).

Almost surely, 2^55784447820 is an apocalyptic number.

It is an amenable number.

55784447820 is an abundant number, since it is smaller than the sum of its proper divisors (121803325620).

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

55784447820 is a wasteful number, since it uses less digits than its factorization.

55784447820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2402492 (or 2402484 counting only the distinct ones).

The product of its (nonzero) digits is 10035200, while the sum is 54.

The spelling of 55784447820 in words is "fifty-five billion, seven hundred eighty-four million, four hundred forty-seven thousand, eight hundred twenty".