681749050441 has 2 divisors, whose sum is σ = 681749050442. Its totient is φ = 681749050440.

The previous prime is 681749050439. The next prime is 681749050453. The reversal of 681749050441 is 144050947186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 672728040000 + 9021010441 = 820200^2 + 94979^2 .

It is a cyclic number.

It is not a de Polignac number, because 681749050441 - 2¹ = 681749050439 is a prime.

Together with 681749050439, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (681749050141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340874525220 + 340874525221.

It is an arithmetic number, because the mean of its divisors is an integer number (340874525221).

Almost surely, 2^681749050441 is an apocalyptic number.

It is an amenable number.

681749050441 is a deficient number, since it is larger than the sum of its proper divisors (1).

681749050441 is an equidigital number, since it uses as much as digits as its factorization.

681749050441 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 681749050441 in words is "six hundred eighty-one billion, seven hundred forty-nine million, fifty thousand, four hundred forty-one".