681819102720 has 640 divisors, whose sum is σ = 2774980961280. Its totient is φ = 155443691520.

The previous prime is 681819102709. The next prime is 681819102743. The reversal of 681819102720 is 27201918186.

It is a tau number, because it is divible by the number of its divisors (640).

It is a super-2 number, since 2×681819102720² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 214339530 + ... + 214342710.

It is an arithmetic number, because the mean of its divisors is an integer number (4335907752).

Almost surely, 2^681819102720 is an apocalyptic number.

681819102720 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 681819102720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1387490480640).

681819102720 is an abundant number, since it is smaller than the sum of its proper divisors (2093161858560).

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

681819102720 is a wasteful number, since it uses less digits than its factorization.

681819102720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3663 (or 3641 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The spelling of 681819102720 in words is "six hundred eighty-one billion, eight hundred nineteen million, one hundred two thousand, seven hundred twenty".