681215105544 has 128 divisors (see below), whose sum is σ = 1766255124480. Its totient is φ = 218713996800.

The previous prime is 681215105539. The next prime is 681215105591. The reversal of 681215105544 is 445501512186.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 681215105496 and 681215105505.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 188857389 + ... + 188860995.

It is an arithmetic number, because the mean of its divisors is an integer number (13798868160).

Almost surely, 2^681215105544 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 681215105544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (883127562240).

681215105544 is an abundant number, since it is smaller than the sum of its proper divisors (1085040018936).

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

681215105544 is a wasteful number, since it uses less digits than its factorization.

681215105544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4771 (or 4767 counting only the distinct ones).

The product of its (nonzero) digits is 192000, while the sum is 42.

The spelling of 681215105544 in words is "six hundred eighty-one billion, two hundred fifteen million, one hundred five thousand, five hundred forty-four".