661083318846720 has 1728 divisors, whose sum is σ = 2883521538293760. Its totient is φ = 135840905625600.

The previous prime is 661083318846703. The next prime is 661083318846737. The reversal of 661083318846720 is 27648813380166.

661083318846720 is a `hidden beast` number, since 6 + 6 + 10 + 83 + 3 + 1 + 88 + 467 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (661083318846703) and next prime (661083318846737).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 35035409446 + ... + 35035428314.

It is an arithmetic number, because the mean of its divisors is an integer number (1668704593920).

Almost surely, 2^{661083318846720} is an apocalyptic number.

661083318846720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661083318846720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1441760769146880).

661083318846720 is an abundant number, since it is smaller than the sum of its proper divisors (2222438219447040).

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

661083318846720 is a wasteful number, since it uses less digits than its factorization.

661083318846720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19352 (or 19335 counting only the distinct ones).

The product of its (nonzero) digits is 55738368, while the sum is 63.

The spelling of 661083318846720 in words is "six hundred sixty-one trillion, eighty-three billion, three hundred eighteen million, eight hundred forty-six thousand, seven hundred twenty".