681337081 has 2 divisors, whose sum is σ = 681337082. Its totient is φ = 681337080.

The previous prime is 681337061. The next prime is 681337109. The reversal of 681337081 is 180733186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 562875625 + 118461456 = 23725^2 + 10884^2 .

It is a cyclic number.

It is not a de Polignac number, because 681337081 - 2¹³ = 681328889 is a prime.

It is a super-2 number, since 2×681337081² = 928440435891201122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 681337081.

It is not a weakly prime, because it can be changed into another prime (681337061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340668540 + 340668541.

It is an arithmetic number, because the mean of its divisors is an integer number (340668541).

Almost surely, 2^681337081 is an apocalyptic number.

It is an amenable number.

681337081 is a deficient number, since it is larger than the sum of its proper divisors (1).

681337081 is an equidigital number, since it uses as much as digits as its factorization.

681337081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 681337081 is about 26102.4343883861. The cubic root of 681337081 is about 879.9419215286.

The spelling of 681337081 in words is "six hundred eighty-one million, three hundred thirty-seven thousand, eighty-one".