6449891494421 has 2 divisors, whose sum is σ = 6449891494422. Its totient is φ = 6449891494420.

The previous prime is 6449891494393. The next prime is 6449891494451. The reversal of 6449891494421 is 1244941989446.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6400647002500 + 49244491921 = 2529950^2 + 221911^2 .

It is a cyclic number.

It is not a de Polignac number, because 6449891494421 - 2³⁴ = 6432711625237 is a prime.

It is a super-2 number, since 2×6449891494421² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6449891494451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3224945747210 + 3224945747211.

It is an arithmetic number, because the mean of its divisors is an integer number (3224945747211).

Almost surely, 2^{6449891494421} is an apocalyptic number.

It is an amenable number.

6449891494421 is a deficient number, since it is larger than the sum of its proper divisors (1).

6449891494421 is an equidigital number, since it uses as much as digits as its factorization.

6449891494421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 71663616, while the sum is 65.

The spelling of 6449891494421 in words is "six trillion, four hundred forty-nine billion, eight hundred ninety-one million, four hundred ninety-four thousand, four hundred twenty-one".