655117657920 has 588 divisors, whose sum is σ = 2570999041380. Its totient is φ = 158809559040.

The previous prime is 655117657891. The next prime is 655117657937. The reversal of 655117657920 is 29756711556.

655117657920 is a `hidden beast` number, since 6 + 5 + 51 + 17 + 6 + 579 + 2 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 364217078016 + 290900579904 = 603504^2 + 539352^2 .

It is a super-2 number, since 2×655117657920² (a number of 24 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 28215276 + ... + 28238484.

Almost surely, 2^655117657920 is an apocalyptic number.

655117657920 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 655117657920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1285499520690).

655117657920 is an abundant number, since it is smaller than the sum of its proper divisors (1915881383460).

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

655117657920 is a wasteful number, since it uses less digits than its factorization.

655117657920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23266 (or 23230 counting only the distinct ones).

The product of its (nonzero) digits is 3969000, while the sum is 54.

The spelling of 655117657920 in words is "six hundred fifty-five billion, one hundred seventeen million, six hundred fifty-seven thousand, nine hundred twenty".