661568083200 has 1512 divisors, whose sum is σ = 2742571339200. Its totient is φ = 156943319040.

The previous prime is 661568083199. The next prime is 661568083247. The reversal of 661568083200 is 2380865166.

661568083200 is a `hidden beast` number, since 6 + 6 + 1 + 568 + 0 + 83 + 2 + 0 + 0 = 666.

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 polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 1506988581 + ... + 1506989019.

Almost surely, 2^661568083200 is an apocalyptic number.

661568083200 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 661568083200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1371285669600).

661568083200 is an abundant number, since it is smaller than the sum of its proper divisors (2081003256000).

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

661568083200 is a wasteful number, since it uses less digits than its factorization.

661568083200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 485 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 661568083200 in words is "six hundred sixty-one billion, five hundred sixty-eight million, eighty-three thousand, two hundred".