661500403200 has 1440 divisors, whose sum is σ = 2950526779200. Its totient is φ = 137806479360.

The previous prime is 661500403189. The next prime is 661500403229. The reversal of 661500403200 is 2304005166.

661500403200 is a `hidden beast` number, since 6 + 6 + 1 + 50 + 0 + 403 + 200 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 933004446 + ... + 933005154.

It is an arithmetic number, because the mean of its divisors is an integer number (2048976930).

Almost surely, 2^661500403200 is an apocalyptic number.

661500403200 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 661500403200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1475263389600).

661500403200 is an abundant number, since it is smaller than the sum of its proper divisors (2289026376000).

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

661500403200 is a wasteful number, since it uses less digits than its factorization.

661500403200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 852 (or 828 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

Adding to 661500403200 its reverse (2304005166), we get a palindrome (663804408366).

The spelling of 661500403200 in words is "six hundred sixty-one billion, five hundred million, four hundred three thousand, two hundred".