681750615881664 has 672 divisors, whose sum is σ = 2395452287185920. Its totient is φ = 191878508828160.

The previous prime is 681750615881659. The next prime is 681750615881681. The reversal of 681750615881664 is 466188516057186.

681750615881664 is a `hidden beast` number, since 6 + 8 + 1 + 7 + 506 + 1 + 58 + 8 + 1 + 6 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 681750615881592 and 681750615881601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 458773129 + ... + 460256759.

Almost surely, 2^{681750615881664} is an apocalyptic number.

681750615881664 is a gapful number since it is divisible by the number (64) 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 681750615881664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1197726143592960).

681750615881664 is an abundant number, since it is smaller than the sum of its proper divisors (1713701671304256).

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

681750615881664 is an equidigital number, since it uses as much as digits as its factorization.

681750615881664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1483745 (or 1483710 counting only the distinct ones).

The product of its (nonzero) digits is 464486400, while the sum is 72.

The spelling of 681750615881664 in words is "six hundred eighty-one trillion, seven hundred fifty billion, six hundred fifteen million, eight hundred eighty-one thousand, six hundred sixty-four".