661035500 has 48 divisors (see below), whose sum is σ = 1446463200. Its totient is φ = 263908800.

The previous prime is 661035499. The next prime is 661035511. The reversal of 661035500 is 5530166.

It is a self number, because there is not a number n which added to its sum of digits gives 661035500.

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 15 ways as a sum of consecutive naturals, for example, 368606 + ... + 370394.

It is an arithmetic number, because the mean of its divisors is an integer number (30134650).

Almost surely, 2^661035500 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661035500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (723231600).

661035500 is an abundant number, since it is smaller than the sum of its proper divisors (785427700).

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

661035500 is a wasteful number, since it uses less digits than its factorization.

661035500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2547 (or 2535 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 26.

The square root of 661035500 is about 25710.6106500799. The cubic root of 661035500 is about 871.1138681399.

Adding to 661035500 its reverse (5530166), we get a palindrome (666565666).

The spelling of 661035500 in words is "six hundred sixty-one million, thirty-five thousand, five hundred".