6449810681 has 2 divisors, whose sum is σ = 6449810682. Its totient is φ = 6449810680.

The previous prime is 6449810639. The next prime is 6449810713. The reversal of 6449810681 is 1860189446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6003925225 + 445885456 = 77485^2 + 21116^2 .

It is a cyclic number.

It is not a de Polignac number, because 6449810681 - 2²² = 6445616377 is a prime.

It is a super-2 number, since 2×6449810681² = 83200115641483367522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6449815681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3224905340 + 3224905341.

It is an arithmetic number, because the mean of its divisors is an integer number (3224905341).

Almost surely, 2^6449810681 is an apocalyptic number.

It is an amenable number.

6449810681 is a deficient number, since it is larger than the sum of its proper divisors (1).

6449810681 is an equidigital number, since it uses as much as digits as its factorization.

6449810681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 331776, while the sum is 47.

The square root of 6449810681 is about 80310.7133637848. The cubic root of 6449810681 is about 1861.4397725154.

The spelling of 6449810681 in words is "six billion, four hundred forty-nine million, eight hundred ten thousand, six hundred eighty-one".