681733945 has 8 divisors (see below), whose sum is σ = 826515144. Its totient is φ = 539764224.

The previous prime is 681733939. The next prime is 681733973. The reversal of 681733945 is 549337186.

681733945 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 83393424 + 598340521 = 9132^2 + 24461^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681733945 - 2¹³ = 681725753 is a prime.

It is a super-2 number, since 2×681733945² = 929522343530526050, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681733895 and 681733904.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 702334 + ... + 703303.

It is an arithmetic number, because the mean of its divisors is an integer number (103314393).

Almost surely, 2^681733945 is an apocalyptic number.

It is an amenable number.

681733945 is a deficient number, since it is larger than the sum of its proper divisors (144781199).

681733945 is a wasteful number, since it uses less digits than its factorization.

681733945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1405739.

The product of its digits is 544320, while the sum is 46.

The square root of 681733945 is about 26110.0353312668. The cubic root of 681733945 is about 880.1127373644.

The spelling of 681733945 in words is "six hundred eighty-one million, seven hundred thirty-three thousand, nine hundred forty-five".