681513 has 32 divisors (see below), whose sum is σ = 1161216. Its totient is φ = 346368.

The previous prime is 681497. The next prime is 681521. The reversal of 681513 is 315186.

It is not a de Polignac number, because 681513 - 2⁴ = 681497 is a prime.

It is a Curzon number.

681513 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (681523) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8170 + ... + 8252.

It is an arithmetic number, because the mean of its divisors is an integer number (36288).

2⁶⁸¹⁵¹³ is an apocalyptic number.

It is an amenable number.

681513 is a deficient number, since it is larger than the sum of its proper divisors (479703).

681513 is a wasteful number, since it uses less digits than its factorization.

681513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133.

The product of its digits is 720, while the sum is 24.

The square root of 681513 is about 825.5380063934. The cubic root of 681513 is about 88.0017647718.

Adding to 681513 its reverse (315186), we get a palindrome (996699).

The spelling of 681513 in words is "six hundred eighty-one thousand, five hundred thirteen".