661236045736 has 64 divisors (see below), whose sum is σ = 1515961008000. Its totient is φ = 264070575360.

The previous prime is 661236045727. The next prime is 661236045773. The reversal of 661236045736 is 637540632166.

It is a self number, because there is not a number n which added to its sum of digits gives 661236045736.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5029051 + ... + 5158858.

It is an arithmetic number, because the mean of its divisors is an integer number (23686890750).

Almost surely, 2^661236045736 is an apocalyptic number.

It is an amenable number.

661236045736 is an abundant number, since it is smaller than the sum of its proper divisors (854724962264).

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

661236045736 is a wasteful number, since it uses less digits than its factorization.

661236045736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10188002 (or 10187998 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 49.

The spelling of 661236045736 in words is "six hundred sixty-one billion, two hundred thirty-six million, forty-five thousand, seven hundred thirty-six".