681240089 has 2 divisors, whose sum is σ = 681240090. Its totient is φ = 681240088.

The previous prime is 681240067. The next prime is 681240107. The reversal of 681240089 is 980042186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 612067600 + 69172489 = 24740^2 + 8317^2 .

It is a cyclic number.

It is not a de Polignac number, because 681240089 - 2⁸ = 681239833 is a prime.

It is not a weakly prime, because it can be changed into another prime (681240589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340620044 + 340620045.

It is an arithmetic number, because the mean of its divisors is an integer number (340620045).

Almost surely, 2^681240089 is an apocalyptic number.

It is an amenable number.

681240089 is a deficient number, since it is larger than the sum of its proper divisors (1).

681240089 is an equidigital number, since it uses as much as digits as its factorization.

681240089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 681240089 is about 26100.5764112596. The cubic root of 681240089 is about 879.9001647245.

The spelling of 681240089 in words is "six hundred eighty-one million, two hundred forty thousand, eighty-nine".