681387841 has 4 divisors (see below), whose sum is σ = 681524784. Its totient is φ = 681250900.

The previous prime is 681387809. The next prime is 681387887. The reversal of 681387841 is 148783186.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 681387841 - 2⁵ = 681387809 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681387791 and 681387800.

It is not an unprimeable number, because it can be changed into a prime (681687841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60715 + ... + 71056.

It is an arithmetic number, because the mean of its divisors is an integer number (170381196).

Almost surely, 2^681387841 is an apocalyptic number.

It is an amenable number.

681387841 is a deficient number, since it is larger than the sum of its proper divisors (136943).

681387841 is a wasteful number, since it uses less digits than its factorization.

681387841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136942.

The product of its digits is 258048, while the sum is 46.

The square root of 681387841 is about 26103.4066933801. The cubic root of 681387841 is about 879.9637730438.

The spelling of 681387841 in words is "six hundred eighty-one million, three hundred eighty-seven thousand, eight hundred forty-one".