21267270709 has 2 divisors, whose sum is σ = 21267270710. Its totient is φ = 21267270708.

The previous prime is 21267270701. The next prime is 21267270749. The reversal of 21267270709 is 90707276212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11683448100 + 9583822609 = 108090^2 + 97897^2 .

It is a cyclic number.

It is not a de Polignac number, because 21267270709 - 2³ = 21267270701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21267270701) 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, 10633635354 + 10633635355.

It is an arithmetic number, because the mean of its divisors is an integer number (10633635355).

Almost surely, 2^21267270709 is an apocalyptic number.

It is an amenable number.

21267270709 is a deficient number, since it is larger than the sum of its proper divisors (1).

21267270709 is an equidigital number, since it uses as much as digits as its factorization.

21267270709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 148176, while the sum is 43.

The spelling of 21267270709 in words is "twenty-one billion, two hundred sixty-seven million, two hundred seventy thousand, seven hundred nine".