655535617920 has 384 divisors, whose sum is σ = 2428449660000. Its totient is φ = 168780423168.

The previous prime is 655535617907. The next prime is 655535617921. The reversal of 655535617920 is 29716535556.

655535617920 is a `hidden beast` number, since 6 + 5 + 5 + 5 + 3 + 561 + 79 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655535617921) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 4437406 + ... + 4582754.

Almost surely, 2^655535617920 is an apocalyptic number.

655535617920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 655535617920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1214224830000).

655535617920 is an abundant number, since it is smaller than the sum of its proper divisors (1772914042080).

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

655535617920 is a wasteful number, since it uses less digits than its factorization.

655535617920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145412 (or 145388 counting only the distinct ones).

The product of its (nonzero) digits is 8505000, while the sum is 54.

The spelling of 655535617920 in words is "six hundred fifty-five billion, five hundred thirty-five million, six hundred seventeen thousand, nine hundred twenty".