661803243936 has 48 divisors (see below), whose sum is σ = 1746234774144. Its totient is φ = 219458064384.

The previous prime is 661803243931. The next prime is 661803243949. The reversal of 661803243936 is 639342308166.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (661803243931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17841016 + ... + 17878071.

It is an arithmetic number, because the mean of its divisors is an integer number (36379891128).

Almost surely, 2^661803243936 is an apocalyptic number.

It is an amenable number.

661803243936 is an abundant number, since it is smaller than the sum of its proper divisors (1084431530208).

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

661803243936 is a wasteful number, since it uses less digits than its factorization.

661803243936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35719293 (or 35719285 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 51.

The spelling of 661803243936 in words is "six hundred sixty-one billion, eight hundred three million, two hundred forty-three thousand, nine hundred thirty-six".