55218638405520 has 80 divisors (see below), whose sum is σ = 190197532293120. Its totient is φ = 14724970240896.

The previous prime is 55218638405467. The next prime is 55218638405531. The reversal of 55218638405520 is 2550483681255.

55218638405520 is a `hidden beast` number, since 5 + 5 + 2 + 1 + 8 + 6 + 3 + 84 + 0 + 552 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12782090064 + ... + 12782094383.

It is an arithmetic number, because the mean of its divisors is an integer number (2377469153664).

Almost surely, 2^{55218638405520} is an apocalyptic number.

It is an amenable number.

55218638405520 is an abundant number, since it is smaller than the sum of its proper divisors (134978893887600).

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

55218638405520 is a wasteful number, since it uses less digits than its factorization.

55218638405520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25564184469 (or 25564184457 counting only the distinct ones).

The product of its (nonzero) digits is 11520000, while the sum is 54.

The spelling of 55218638405520 in words is "fifty-five trillion, two hundred eighteen billion, six hundred thirty-eight million, four hundred five thousand, five hundred twenty".