661080600 has 144 divisors (see below), whose sum is σ = 2229734520. Its totient is φ = 175526400.

The previous prime is 661080569. The next prime is 661080613. The reversal of 661080600 is 6080166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 505147 + ... + 506453.

Almost surely, 2^661080600 is an apocalyptic number.

661080600 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 661080600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1114867260).

661080600 is an abundant number, since it is smaller than the sum of its proper divisors (1568653920).

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

661080600 is a wasteful number, since it uses less digits than its factorization.

661080600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1610 (or 1598 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 661080600 is about 25711.4877049151. The cubic root of 661080600 is about 871.1336786453.

The spelling of 661080600 in words is "six hundred sixty-one million, eighty thousand, six hundred".