2021308120649 has 2 divisors, whose sum is σ = 2021308120650. Its totient is φ = 2021308120648.

The previous prime is 2021308120631. The next prime is 2021308120721. The reversal of 2021308120649 is 9460218031202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1561732594249 + 459575526400 = 1249693^2 + 677920^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021308120649 is a prime.

It is not a weakly prime, because it can be changed into another prime (2021308128649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010654060324 + 1010654060325.

It is an arithmetic number, because the mean of its divisors is an integer number (1010654060325).

Almost surely, 2^{2021308120649} is an apocalyptic number.

It is an amenable number.

2021308120649 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021308120649 is an equidigital number, since it uses as much as digits as its factorization.

2021308120649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 38.

The spelling of 2021308120649 in words is "two trillion, twenty-one billion, three hundred eight million, one hundred twenty thousand, six hundred forty-nine".