681377 has 8 divisors (see below), whose sum is σ = 729000. Its totient is φ = 634624.

The previous prime is 681371. The next prime is 681403. The reversal of 681377 is 773186.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2401 + 678976 = 49^2 + 824^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681377 - 2⁴ = 681361 is a prime.

It is a super-2 number, since 2×681377² = 928549232258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681371) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2399 + ... + 2667.

It is an arithmetic number, because the mean of its divisors is an integer number (91125).

2⁶⁸¹³⁷⁷ is an apocalyptic number.

It is an amenable number.

681377 is a deficient number, since it is larger than the sum of its proper divisors (47623).

681377 is a wasteful number, since it uses less digits than its factorization.

681377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435.

The product of its digits is 7056, while the sum is 32.

The square root of 681377 is about 825.4556317574. The cubic root of 681377 is about 87.9959106226.

Subtracting 681377 from its reverse (773186), we obtain a square (91809 = 303²).

It can be divided in two parts, 68 and 1377, that multiplied together give a square (93636 = 306²).

The spelling of 681377 in words is "six hundred eighty-one thousand, three hundred seventy-seven".