681234689 has 4 divisors (see below), whose sum is σ = 681369156. Its totient is φ = 681100224.

The previous prime is 681234661. The next prime is 681234739. The reversal of 681234689 is 986432186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 986432186 = 2 ⋅493216093.

It can be written as a sum of positive squares in 2 ways, for example, as 318979600 + 362255089 = 17860^2 + 19033^2 .

It is a cyclic number.

It is not a de Polignac number, because 681234689 - 2²⁴ = 664457473 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (681234629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59324 + ... + 69869.

It is an arithmetic number, because the mean of its divisors is an integer number (170342289).

Almost surely, 2^681234689 is an apocalyptic number.

It is an amenable number.

681234689 is a deficient number, since it is larger than the sum of its proper divisors (134467).

681234689 is a wasteful number, since it uses less digits than its factorization.

681234689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134466.

The product of its digits is 497664, while the sum is 47.

The square root of 681234689 is about 26100.4729650633. The cubic root of 681234689 is about 879.8978398107.

The spelling of 681234689 in words is "six hundred eighty-one million, two hundred thirty-four thousand, six hundred eighty-nine".