661040055303056 has 160 divisors (see below), whose sum is σ = 1510661817705600. Its totient is φ = 276256108707840.

The previous prime is 661040055303049. The next prime is 661040055303073. The reversal of 661040055303056 is 650303550040166.

661040055303056 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a junction number, because it is equal to n+sod(n) for n = 661040055302998 and 661040055303016.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7778821175 + ... + 7778906153.

It is an arithmetic number, because the mean of its divisors is an integer number (9441636360660).

Almost surely, 2^{661040055303056} 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 661040055303056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (755330908852800).

661040055303056 is an abundant number, since it is smaller than the sum of its proper divisors (849621762402544).

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

661040055303056 is a wasteful number, since it uses less digits than its factorization.

661040055303056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98497 (or 98491 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 44.

The spelling of 661040055303056 in words is "six hundred sixty-one trillion, forty billion, fifty-five million, three hundred three thousand, fifty-six".