681571 has 4 divisors (see below), whose sum is σ = 743544. Its totient is φ = 619600.

The previous prime is 681563. The next prime is 681589. The reversal of 681571 is 175186.

It is a happy number.

681571 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 681571 - 2³ = 681563 is a prime.

It is a Duffinian number.

681571 is a lucky number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (681521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30970 + ... + 30991.

It is an arithmetic number, because the mean of its divisors is an integer number (185886).

2⁶⁸¹⁵⁷¹ is an apocalyptic number.

681571 is a deficient number, since it is larger than the sum of its proper divisors (61973).

681571 is a wasteful number, since it uses less digits than its factorization.

681571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61972.

The product of its digits is 1680, while the sum is 28.

The square root of 681571 is about 825.5731342528. The cubic root of 681571 is about 88.0042611573.

It can be divided in two parts, 6815 and 71, that added together give a palindrome (6886).

The spelling of 681571 in words is "six hundred eighty-one thousand, five hundred seventy-one".