681445539 has 24 divisors (see below), whose sum is σ = 1030013712. Its totient is φ = 433667520.

The previous prime is 681445517. The next prime is 681445549. The reversal of 681445539 is 935544186.

681445539 is a `hidden beast` number, since 68 + 14 + 45 + 539 = 666.

It is not a de Polignac number, because 681445539 - 2⁹ = 681445027 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 681445494 and 681445503.

It is not an unprimeable number, because it can be changed into a prime (681445549) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1657 + ... + 36954.

It is an arithmetic number, because the mean of its divisors is an integer number (42917238).

Almost surely, 2^681445539 is an apocalyptic number.

681445539 is a deficient number, since it is larger than the sum of its proper divisors (348568173).

681445539 is a wasteful number, since it uses less digits than its factorization.

681445539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38707 (or 38704 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 681445539 is about 26104.5118514022. The cubic root of 681445539 is about 879.9886099593.

The spelling of 681445539 in words is "six hundred eighty-one million, four hundred forty-five thousand, five hundred thirty-nine".