661006500500 has 48 divisors (see below), whose sum is σ = 1443720532800. Its totient is φ = 264387520800.

The previous prime is 661006500493. The next prime is 661006500527. The reversal of 661006500500 is 5005600166.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13845671 + ... + 13893329.

It is an arithmetic number, because the mean of its divisors is an integer number (30077511100).

Almost surely, 2^661006500500 is an apocalyptic number.

It is an amenable number.

661006500500 is an abundant number, since it is smaller than the sum of its proper divisors (782714032300).

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

661006500500 is a wasteful number, since it uses less digits than its factorization.

661006500500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75417 (or 75405 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 29.

The spelling of 661006500500 in words is "six hundred sixty-one billion, six million, five hundred thousand, five hundred".