681755 has 4 divisors (see below), whose sum is σ = 818112. Its totient is φ = 545400.

The previous prime is 681731. The next prime is 681763. The reversal of 681755 is 557186.

681755 = 136² + 137² + ... + 165².

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

It is not a de Polignac number, because 681755 - 2¹⁶ = 616219 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 68171 + ... + 68180.

It is an arithmetic number, because the mean of its divisors is an integer number (204528).

2⁶⁸¹⁷⁵⁵ is an apocalyptic number.

681755 is a deficient number, since it is larger than the sum of its proper divisors (136357).

681755 is a wasteful number, since it uses less digits than its factorization.

681755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136356.

The product of its digits is 8400, while the sum is 32.

The square root of 681755 is about 825.6845644676. The cubic root of 681755 is about 88.0121797880.

The spelling of 681755 in words is "six hundred eighty-one thousand, seven hundred fifty-five".