1299811021 has 2 divisors, whose sum is σ = 1299811022. Its totient is φ = 1299811020.

The previous prime is 1299810989. The next prime is 1299811039. The reversal of 1299811021 is 1201189921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 729270025 + 570540996 = 27005^2 + 23886^2 .

It is an emirp because it is prime and its reverse (1201189921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1299811021 - 2⁵ = 1299810989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1299821021) 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, 649905510 + 649905511.

It is an arithmetic number, because the mean of its divisors is an integer number (649905511).

Almost surely, 2^1299811021 is an apocalyptic number.

It is an amenable number.

1299811021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1299811021 is an equidigital number, since it uses as much as digits as its factorization.

1299811021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 34.

The square root of 1299811021 is about 36052.8919921828. The cubic root of 1299811021 is about 1091.3399957969.

The spelling of 1299811021 in words is "one billion, two hundred ninety-nine million, eight hundred eleven thousand, twenty-one".