6420996649 has 2 divisors, whose sum is σ = 6420996650. Its totient is φ = 6420996648.

The previous prime is 6420996623. The next prime is 6420996677. The reversal of 6420996649 is 9466990246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4165411600 + 2255585049 = 64540^2 + 47493^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6420996649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6420996649.

It is not a weakly prime, because it can be changed into another prime (6420996689) 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, 3210498324 + 3210498325.

It is an arithmetic number, because the mean of its divisors is an integer number (3210498325).

Almost surely, 2^6420996649 is an apocalyptic number.

It is an amenable number.

6420996649 is a deficient number, since it is larger than the sum of its proper divisors (1).

6420996649 is an equidigital number, since it uses as much as digits as its factorization.

6420996649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5038848, while the sum is 55.

The square root of 6420996649 is about 80131.1216007863. The cubic root of 6420996649 is about 1858.6636881930.

The spelling of 6420996649 in words is "six billion, four hundred twenty million, nine hundred ninety-six thousand, six hundred forty-nine".