681777 has 20 divisors (see below), whose sum is σ = 1074480. Its totient is φ = 429624.

The previous prime is 681773. The next prime is 681781. The reversal of 681777 is 777186.

681777 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (681773) and next prime (681781).

It is not a de Polignac number, because 681777 - 2² = 681773 is a prime.

It is a super-3 number, since 3×681777³ = 950710505335333299, which contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (681773) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1318 + ... + 1760.

It is an arithmetic number, because the mean of its divisors is an integer number (53724).

2⁶⁸¹⁷⁷⁷ is an apocalyptic number.

It is an amenable number.

681777 is a deficient number, since it is larger than the sum of its proper divisors (392703).

681777 is a wasteful number, since it uses less digits than its factorization.

681777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 474 (or 465 counting only the distinct ones).

The product of its digits is 16464, while the sum is 36.

The square root of 681777 is about 825.6978866389. The cubic root of 681777 is about 88.0131264854.

The spelling of 681777 in words is "six hundred eighty-one thousand, seven hundred seventy-seven".