681481 has 2 divisors, whose sum is σ = 681482. Its totient is φ = 681480.

The previous prime is 681451. The next prime is 681487. The reversal of 681481 is 184186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 665856 + 15625 = 816^2 + 125^2 .

It is a cyclic number.

It is not a de Polignac number, because 681481 - 2⁵ = 681449 is a prime.

It is a super-2 number, since 2×681481² = 928832706722, which contains 22 as substring.

681481 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (681487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340740 + 340741.

It is an arithmetic number, because the mean of its divisors is an integer number (340741).

2⁶⁸¹⁴⁸¹ is an apocalyptic number.

It is an amenable number.

681481 is a deficient number, since it is larger than the sum of its proper divisors (1).

681481 is an equidigital number, since it uses as much as digits as its factorization.

681481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1536, while the sum is 28.

The square root of 681481 is about 825.5186248656. The cubic root of 681481 is about 88.0003873950. Note that the first 3 decimals are identical.

The spelling of 681481 in words is "six hundred eighty-one thousand, four hundred eighty-one".