681329538 has 24 divisors (see below), whose sum is σ = 1527119100. Its totient is φ = 219278304.

The previous prime is 681329527. The next prime is 681329599. The reversal of 681329538 is 835923186.

It is a happy number.

681329538 is a `hidden beast` number, since 6 + 81 + 32 + 9 + 538 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 648873729 + 32455809 = 25473^2 + 5697^2 .

It is a junction number, because it is equal to n+sod(n) for n = 681329493 and 681329502.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 652093 + ... + 653136.

Almost surely, 2^681329538 is an apocalyptic number.

681329538 is an abundant number, since it is smaller than the sum of its proper divisors (845789562).

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

681329538 is a wasteful number, since it uses less digits than its factorization.

681329538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1305266 (or 1305263 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 681329538 is about 26102.2898995471. The cubic root of 681329538 is about 879.9386742732.

The spelling of 681329538 in words is "six hundred eighty-one million, three hundred twenty-nine thousand, five hundred thirty-eight".