6649781293 has 2 divisors, whose sum is σ = 6649781294. Its totient is φ = 6649781292.

The previous prime is 6649781273. The next prime is 6649781297. The reversal of 6649781293 is 3921879466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5455595044 + 1194186249 = 73862^2 + 34557^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6649781293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6649781297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3324890646 + 3324890647.

It is an arithmetic number, because the mean of its divisors is an integer number (3324890647).

Almost surely, 2^6649781293 is an apocalyptic number.

It is an amenable number.

6649781293 is a deficient number, since it is larger than the sum of its proper divisors (1).

6649781293 is an equidigital number, since it uses as much as digits as its factorization.

6649781293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3919104, while the sum is 55.

The square root of 6649781293 is about 81546.1911618194. The cubic root of 6649781293 is about 1880.4817398516.

The spelling of 6649781293 in words is "six billion, six hundred forty-nine million, seven hundred eighty-one thousand, two hundred ninety-three".