21000221339 has 2 divisors, whose sum is σ = 21000221340. Its totient is φ = 21000221338.

The previous prime is 21000221309. The next prime is 21000221353. The reversal of 21000221339 is 93312200012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000221339 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000221309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500110669 + 10500110670.

It is an arithmetic number, because the mean of its divisors is an integer number (10500110670).

Almost surely, 2^21000221339 is an apocalyptic number.

21000221339 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000221339 is an equidigital number, since it uses as much as digits as its factorization.

21000221339 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The spelling of 21000221339 in words is "twenty-one billion, two hundred twenty-one thousand, three hundred thirty-nine".