655216660800 has 504 divisors, whose sum is σ = 2575741966616. Its totient is φ = 156923412480.

The previous prime is 655216660793. The next prime is 655216660841. The reversal of 655216660800 is 8066612556.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 28636762176 + 626579898624 = 169224^2 + 791568^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6879102 + ... + 6973698.

Almost surely, 2^655216660800 is an apocalyptic number.

655216660800 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 655216660800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1287870983308).

655216660800 is an abundant number, since it is smaller than the sum of its proper divisors (1920525305816).

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

655216660800 is a wasteful number, since it uses less digits than its factorization.

655216660800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94675 (or 94657 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 655216660800 in words is "six hundred fifty-five billion, two hundred sixteen million, six hundred sixty thousand, eight hundred".