661116600 has 192 divisors, whose sum is σ = 2376633600. Its totient is φ = 168600960.

The previous prime is 661116593. The next prime is 661116611. The reversal of 661116600 is 6611166.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 121539 + ... + 126861.

It is an arithmetic number, because the mean of its divisors is an integer number (12378300).

Almost surely, 2^661116600 is an apocalyptic number.

661116600 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 661116600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1188316800).

661116600 is an abundant number, since it is smaller than the sum of its proper divisors (1715517000).

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

661116600 is a wasteful number, since it uses less digits than its factorization.

661116600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5371 (or 5356 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 661116600 is about 25712.1877715608. The cubic root of 661116600 is about 871.1494912624.

Adding to 661116600 its reverse (6611166), we get a palindrome (667727766).

661116600 divided by its reverse (6611166) gives a square (100 = 10²).

The spelling of 661116600 in words is "six hundred sixty-one million, one hundred sixteen thousand, six hundred".